how to print array in reverse orderhow to print array in reverse order

Solution Python #Initialize array arr = [1, 2, 3, 4, 5]; print("Original array: "); for i in range (0, len (arr)): print(arr [i]), print("Array in reverse order: "); #Loop through the array in reverse order for i in range (len (arr)-1, -1, -1): print(arr [i]), Output: Original array: 1 2 3 4 5 Array in reverse order: 5 4 3 2 1 C #include <stdio.h> @user3386109 has already mentioned several. rev2023.7.14.43533. That means you can not add any kind of manually user-defined function in your code like myFunction(), and so on. If you read this far, tweet to the author to show them you care. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. By clicking Post Your Answer, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct. Copyright Tutorials Point (India) Private Limited. Write a program to compute the sum of elements in an array using recursion. Reversing an array means printing the array elements in the reverse order. Affordable solution to train a team and make them project ready. Arrays can be sorted in ascending or descending order. Note: The time and space complexity of the above approaches For and While loop is the same. 589). @user3386109 has already mentioned several. hasPrevious () method returns true if an element is present at the back of the current element, traverse . Also, you never know when this knowledge will help you later, right? In many cases, the values stored in an array appear in a random order. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Asking for help, clarification, or responding to other answers. JavaTpoint offers college campus training on Core Java, Advance Java, .Net, Android, Hadoop, PHP, Web Technology and Python. Control two leds with only one PIC output, The shorter the message, the larger the prize, Do symbolic integration of function including \[ScriptCapitalL]. Why can you not divide both sides of the equation, when working with exponential functions? You have to use a user-defined function for printing the array in reverse order. Right now it is counting from 0 to the length, have it count from the length to zero for (int i = array.length-1; i >= 0; i--) Share Improve this answer Follow answered Jun 13, 2014 at 13:05 JavaTpoint offers college campus training on Core Java, Advance Java, .Net, Android, Hadoop, PHP, Web Technology and Python. A vector can be printed in reverse order with the following methods: By traversing in the backward direction using indexing By traversing in the backward direction using begin () and end () functions in C++ STL By traversing in the backward direction using rbegin () and rend () functions in C++ STL Examples: By using this website, you agree with our Cookies Policy. The Overflow #186: Do large language models know what theyre talking about? Also, if you like to solve problems using programming languages, then make sure to check my ongoing YouTube playlist where I solve problems using the programming language. Now it is time to print all the array elements (the value that each index of the array has) in the given order. Thats the only way we can improve. An exercise in Data Oriented Design & Multi Threading in C++. Get started, freeCodeCamp is a donor-supported tax-exempt 501(c)(3) charity organization (United States Federal Tax Identification Number: 82-0779546). This give us access to all the methods of the Arrays class. Now, this time the criteria has been changed. Approach 1 - Backward looping The most obvious approach is to loop through the elements. I am pretty new in this coding world. You have to use a user-defined function for printing the array in reverse order. Developed by JavaTpoint. (Ep. For example, if we want to increment each element value by 10 in a container, then we can use std::for_each() for that. The OP is asking for an explanation of existing code (that's likely intentionally avoiding slicing), not a "better way to do it". But if you write the entire printReversely(int arr[], int arraySize) function before the main() function then you do not necessarily need to add the declaration again before that. Is this gap under my patio sidelights okay? Then call the Collections.reverse() method to reverse the order of the elements in the list. How should a time traveler be careful if they decide to stay and make a family in the past? For this article, I will be using the C++ programming language. Tweet a thanks, Learn to code for free. Be the first to rate this post. Asking for help, clarification, or responding to other answers. JavaTpoint offers too many high quality services. Declare an ArrayList. Is this color scheme another standard for RJ45 cable? Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing. We can sort arrays in ascending order using the sort() method which can be accessed from the Arrays class. First, we will create an array and then use the for loop to print the array elements in reverse order. In this program, we need to print the elements of the array in reverse order that is; the last element should be displayed first, followed by second last element and so on. I will go through the process to help you understand what you would need to do from the beginning for solving the problem. The above code can be rewritten as below with more readability. C program to print the elements of an array in reverse order with c, language, what is c programming, interview questions, number programs, array programs, pronic numbers, harshad number, happy numbers, disarium numbers, c programs, fibonacci series, circular linked list programs, doubly linked list programs etc. Examples. You can also SUBSCRIBE to my YouTube channel (Code With FahimFBA) if you want to learn various kinds of programming languages with a lot of practical examples regularly. This way we can print the values of an array in reverse order. For example, I am going to name the new user-defined function printReversely(int arr[], int arraySize). Here's an example: 5 Answers Sorted by: 2 In Python3: if __name__ == '__main__': n = int (input ()) arr = list (map (int, input ().rstrip ().split ())) print (" ".join (str (x) for x in arr [::-1])) Input: 1 4 3 2 Output: Loop through the array in reverse order that is, the loop will start from (length of the array - 1) and end at 0 by decreasing the value of i by 1. This is not work, you need to use this code: This function will receive address of array in pointer variable and it will receive the size of array The first line contains an integer N, (the size of our array). Do NOT follow this link or you will be banned from the site. my ongoing YouTube playlist where I solve problems using the programming language. Mail us on h[emailprotected], to get more information about given services. In C/C++, if you declare an array without initializing the value, then you need to specify the array size as well. This can be easily done using a for loop: The above solution uses two indices, one for each end of the array. All rights reserved. To print an array in reverse order, we shall know the length of the array in advance. 7 Answers Sorted by: 82 Arrays in Java are indexed from 0 to length - 1, not 1 to length, therefore you should be assign your variable accordingly and use the correct comparison operator. We then created an array of numbers in random order: Integer[] arr = { 5, 2, 1, 8, 10 };. Keep in mind that the array always starts from the 0 index (the first element is at index 0, the second is at index 1, and so on). This post will discuss how to print the contents of an array in reverse order in Java. All rights reserved. main invokes print with -> print(n) print() invokes -> print(n-1) To know more on the RAPTOR procedure, follow the link: in this example, size is 4. Another good alternative is to use the output iterator std::ostream_iterator to print array contents to the output stream std::cout. eg. So, let's dive into the question real quick and see how it works. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Find the element that appears once while all the other element appears twice in an array, Sort an array of integers according to the parity; even elements first then odd, The minimum absolute difference between two elements in an Array, Find the sum of all the elements in an array, Print the elements of an array in reverse order in C++, Implementation of Approach 1 While loop, Approach 2 Using Boost Librarys reverse adaptor, Approach 3 Using reverse_copy() and output iterator, Implementation of Approach 5 Using a function object, Implementation of Approach 5 Using the lambda expressions. C# Print an array of strings in the reverse order Ask Question Asked 2 years, 9 months ago Modified 2 years, 9 months ago Viewed 1k times -5 so I have a problem where when I open my program and select 4 which is supposed to make it display all of the strings in the array but in reverse. Copyright 2011-2021 www.javatpoint.com. Print a string which has the reverse order. When a customer buys a product with a credit card, does the seller receive the money in installments or completely in one transaction? Printing Array In Reverse Order using Recursive function, How terrifying is giving a conference talk? We also have thousands of freeCodeCamp study groups around the world. Thank you so much for time and the effort in explaining ! Let's first see what should be the step-by-step procedure of this program , Let's now see the pseudocode of this algorithm , The implementation of the above derived pseudocode is as follows , Enjoy unlimited access on 5500+ Hand Picked Quality Video Courses. This is passed in as a second parameter in the sort() method so that the sorted array can be rearranged in descending order. Let us know if you liked the post. STEP 3: Print the element arr [i] in each iteration. int [] arr = { 35, 12, 66, 90, 34, 2, 64 }; Now, use the following to reverse Array.Reverse (arr); The following is the complete code to reverse a one-dimensional array; Example Live Demo The print() procedure is recursive. Then we will create the array with the given array size. By clicking Post Your Answer, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct. The reverse() method reverses an array in place and returns the reference to the same array, the first array element now becoming the last, and the last array element becoming the first. To get a new reversed list, apply the reversed function and collect the items into a list: >>> xs = [0, 10, 20, 40] >>> list (reversed (xs)) [40, 20, 10, 0] To iterate backwards through a list: >>> xs = [0, 10, 20, 40] >>> for x in reversed (xs): . Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing. Why can many languages' futures not be canceled? Not the answer you're looking for? You can name it however you want by following the naming conventions of C++ (or whatever programming language you're using). Pros and cons of "anything-can-happen" UB versus allowing particular deviations from sequential progran execution, Multiplication implemented in c++ with constant time, Can't update or install app with new Google Account. from the last element to the first element: @media(min-width:0px){#div-gpt-ad-codevscolor_com-medrectangle-3-0-asloaded{max-width:728px!important;max-height:90px!important}}if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[728,90],'codevscolor_com-medrectangle-3','ezslot_9',159,'0','0'])};__ez_fad_position('div-gpt-ad-codevscolor_com-medrectangle-3-0');We will use a loop to do that. The first parameter is the array arr which will be sorted in ascending order. The index starts from 0 and ends at length of the array - 1. sci-fi novel from the 60s 70s or 80s about two civilizations in conflict that are from the same world. Get started, freeCodeCamp is a donor-supported tax-exempt 501(c)(3) charity organization (United States Federal Tax Identification Number: 82-0779546). For example if a is an array of integers with three elements such that a [0] = 1 a [1] = 2 a [2] = 3 Then on reversing the array will be a [0] = 3 a [1] = 2 a [0] = 1 Given below is the c code to reverse an array. The range() function returns a sequence of numbers starts from a given number to another given number with a given step. Developed by JavaTpoint. We can use a for loop or a while loop to write this. So, split(' '). Well then, after declaring our array, we will take the array elements from the user. We are sorry that this post was not useful for you! JavaTpoint offers too many high quality services. I have come to help you. Enter your email address to subscribe to new posts. If you run this program, it will print the below output: We need to use the range function to iterate over the array using a for loop. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Then we can start an iteration from length value of array to zero and in each iteration we can print value of array index. Just Simply pass the name of the array. The sort() method takes in the array to be sorted as a parameter. If you want to check out my highlights, then you can do so at my Polywork timeline. Why was there a second saw blade in the first grail challenge? Can someone please explain it to me. Example: var arr = [1,2,3,4,5]; var size = arr.length; for(var i = size -1; i >=0; i --) { console.log( `Element $ { i +1} is $ { arr [ i]} `); } Output Element 5 is 5 Element 4 is 4 Element 3 is 3 Element 2 is 2 Element 1 is 1 Explanation printing array elements from index -1. and the end argument is used to end the print statement with given character, here the end character is " ". In this tutorial, we'll explore how to print a given number in the reverse order in Bash while preserving the negative or positive sign symbol that may appear at its beginning. If you want to get in touch with me, then you can do so using Twitter, LinkedIn, and GitHub. How to print one dimensional array in reverse order? ( code and outcome included ). Instead of looping forward, we will loop backwards as we want to print the elements in reverse order. You can't use any user-defined function. 1. Implementation of Approach 1 - For loop #include <iostream> // IO int main() { Then we can start an iteration from length value of array to zero and in each iteration we can print value of array index. This program reverses the array elements. A simple solution to print the array contents in reverse order is using a simple for loop. We'll still make use of Arrays.sort ();, but in this example, it'll take in two parameters - the array to be sorted and Collections.reverseOrder (). For this article, I will be using only one question but with two different criteria. for i in range(len(arr)): The for loop will iterate from index 0 to length of the array. 1. The only difference is that we need to use a user defined function right now. Through this, you can solve the problem easily. Why is that so many apps today require MacBook with a M1 chip? How to print the alphabets in alternate reverse and alphabetical order? Share But trust me, you do need to understand how to save memory as that is one of the biggest concerns in today's world. To learn more, see our tips on writing great answers. In this way, we can take each value from the user and store it in our array in a sequential way. Python program to check if a number is prime or not, Python program to convert inches to millimeters, Python program to convert millimeters to inches, 5 different ways to print multiple values in Python, How to use empty_like in numpy with example, 3 ways to concatenate tuple elements by delimeter in Python, The while loop keeps running while the value of, Inside the loop, we are printing the element for index. The first thing we did in the example above was to import the Arrays class: import java.util.Arrays;. We can do it with the help of std::copy, which takes the reverse iterator to the starting and ending positions of the array and the output iterator. In python, array index start from 0. When looped through and printed, the array would look like this: 10, 8, 5, 2, 1. You'll notice that we used Integer[] instead of int[] like we did in the last example the latter would throw an error. Write a Program to Find maximum and minimum elements in the array using recursion. While calling the function you should not place [] when you are passing an array. The main then invokes the procedure print. arr_one is a variable, this variable stores each element after split. To sort the array in descending order, we did this: Arrays.sort(arr, Collections.reverseOrder());. Since a range is just a pair of iterators, an adaptor returns a new pair. So first, we want the user to input the array size (how many numbers they want us to process). This method does not reverse the array. Printing the elements of a vector in reverse order, Implementation of Approach 5 Using a unary function. The idea is to create a new array of the same size as the original array. I have tried the following, however I looked at the solution page. STEP 1: Declare and initialize an array. We then created an array with numbers in a random order: int[] arr = { 5, 2, 1, 8, 10 };. The method input() will take the user input from key board. After reaching the last element of ArrayList traverse by using iterator. Our goal is to reverse any given number provided as input, such as 1234, -1234, and 1.234. std::for_each(first,last,fn) applies a function fn to each of the elements in the range[first, last). But if you can understand the core concept then you can use any other programming language to solve this problem. Save my name, email, and website in this browser for the next time I comment. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Create an integer array. the input is not space seperated. Denys Fisher, of Spirograph fame, using a computer late 1976, early 1977, Driving average values with limits in blender. int(input()) will convert the input into int, if the input is in string format. We'll also see how to sort an array in descending order using the reverseOrder() method from the Collections class in Java. If it helps you then you can also check out other articles of mine at freeCodeCamp. So, if you take a larger array than you actually need, you will waste memory, as it takes the full space in memory for the full array whether you use all the indexes or not. The loop starts at the end of the array, prints the current element, and decrement the index by 1 at every iteration. How do I reverse an int array in Java? Write a Program to print array elements using recursion. 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The input value stored into variable n. The Array input will be like this "1 2 3 4". Our mission: to help people learn to code for free. Donations to freeCodeCamp go toward our education initiatives, and help pay for servers, services, and staff. They return a new range based on another range. Thanks for reading the entire article. 2. The values are stored in sequential order in an array and we can access these elements or values by using the index. Well, as today's computers are more powerful, you would likely not notice any differences in memory wastage, as it would be pretty negligible. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. First things first, we imported the Arrays and Collections classes because we'll be making use the methods provided by the classes. The second parameter Collections.reverseOrder() will then reverse the order of the sorted array so it is arranged in descending order. Note that the Arrays class was written first before accessing the sort() method using dot notation. We and our partners share information on your use of this website to help improve your experience. - user4668606 That's it! We can think ofadaptorsas filters. Read our. Take the array elements as input from the user and print all the array elements in the given order and later in the reverse order. Does air in the atmosphere get friction as the planet rotates? If you are the kind of person that loves to follow along with a video too, I have also created a video for you: For solving any kind of problem, the first thing you have to do is to understand the question first. The most obvious approach is to loop through the elements. The OP is asking for an explanation of the existing code, not improved code. Learn more. Answer: There are three methods to reverse an array in Java. For printing the array in reverse order, we can simply print the array in a backwards direction. If you do not do that, then you'll get an error. Task Description. Pretty easy problem, we will see all the different ways to solve it. Create an integer array. Then the function displays array in reverse order. For example, if the array is [1, 2, 3, 4, 5], it will print it in reverse order i.e. The loop structure should look like for (i=size-1; i>=0; i--). This leads to misbehaviour, since element x in the array will be printed n - x times this way. Thats all about printing contents of an array in reverse order in Java. // size of n ArrayList<Integer> List = new ArrayList<Integer> (n); 2. Notice that we did not use any kind of user-defined function in our entire code. We accomplish this by creating thousands of videos, articles, and interactive coding lessons - all freely available to the public. Take the array elements as input from the user and print all the array elements in the given order and later in reverse order. We make use of First and third party cookies to improve our user experience. @media(min-width:0px){#div-gpt-ad-codevscolor_com-box-4-0-asloaded{max-width:336px!important;max-height:280px!important}}if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[336,280],'codevscolor_com-box-4','ezslot_4',160,'0','0'])};__ez_fad_position('div-gpt-ad-codevscolor_com-box-4-0');To print the elements of the array in reverse, we need to use a loop that will iterate from length - 1 to 0. In this section, we'll see an example on how we can use the sort() method to sort an array in ascending order. The loop starts at the end of the array, prints the current element, and decrement the index by 1 at every iteration. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. STEP 2: Loop through the array in reverse order that is, the loop will start from (length of the array - 1) and end at 0 by decreasing the value of i by 1.