Move all digits to the beginning of a given string Last Updated : 23 Jul, 2025 Comments Improve Suggest changes Like Article Like Report Given a string S, the task is to move all the digits present in the string, to the beginning of the string. Examples: Input: S = “Geeks4forGeeks123”Output: 4123GeeksforGeeksExplanation:The given string contains digits 4, 1, 2, and 3. Moving all the digits to the beginning of the string modifies the string to "4123GeeksforGeeks". Input: S = “GeeksforGeeks1234 A Com56puter Science Port7al”Output: 1234567GeeksforGeeks A Computer Science Portal Approach: The idea is to traverse the string and maintain two strings, one string contains the digits and another string contains non-numeric characters. In the end, append both the strings to the result in the required order. Below is the implementation of the above approach: C++ // CPP program for the above approach #include <bits/stdc++.h> using namespace std; // Function to move all the digit // to the beginning of the string void moveAllDigitAtBeginning( string str) { // Calculate the string length int len = str.size(); // Stores the digits string digits = ""; // Stores the non-numeric character string nonNumericCharacter = ""; // Traverse the string and // check if there is a digit for (int i = 0; i < str.size(); i++) { char c = str[i]; // If character is a digit, // add it to the string digits if (c >= 48 && c <= 57) { digits += c; } // Otherwise, add it to the // string nonNumericCharacter else { nonNumericCharacter += c; } } // Append both the strings digits += nonNumericCharacter; // Print the string cout << digits << endl; } // Driver Code int main() { // Given String str string str = "GeeksforGeeks123"; moveAllDigitAtBeginning(str); return 0; } // this code is contributed by harimahecha Java // Java program for the above approach class GFG { // Function to move all the digit // to the beginning of the string static void moveAllDigitAtBeginning( String str) { // Calculate the string length int len = str.length(); // Stores the digits StringBuilder digits = new StringBuilder(); // Stores the non-numeric character StringBuilder nonNumericCharacter = new StringBuilder(); // Traverse the string and // check if there is a digit for (char c : str.toCharArray()) { // If character is a digit, // add it to the string digits if (c >= 48 && c <= 57) { digits.append(c); } // Otherwise, add it to the // string nonNumericCharacter else { nonNumericCharacter.append(c); } } // Append both the strings digits.append( nonNumericCharacter.toString()); // Print the string System.out.print( digits.toString() + " "); } // Driver Code public static void main(String args[]) { // Given String str String str = "GeeksforGeeks123"; moveAllDigitAtBeginning(str); } } Python3 # Python program for the above approach # Function to move all the digit # to the beginning of the string def moveAllDigitAtBeginning(str): # Calculate the string length Len=len(str) # Stores the digits digits="" # Stores the non-numeric character nonNumericCharacter="" # Traverse the string and # check if there is a digit for i in range(len(str)): c=str[i] # If character is a digit, # add it to the string digits if(ord(c)>=48 and ord(c)<=57): digits+=c # Otherwise, add it to the # string nonNumericCharacter else: nonNumericCharacter+=c # Append both the strings digits+=nonNumericCharacter # Print the string print(digits) # Driver Code # Given String str str="GeeksforGeeks123" moveAllDigitAtBeginning(str) # This code is contributed by Aman Kumar C# // C# program for the above approach using System; public class GFG{ // Function to move all the digit // to the beginning of the string static void moveAllDigitAtBeginning(string str) { // Calculate the string length int len = str.Length; // Stores the digits string digits = ""; // Stores the non-numeric character string nonNumericCharacter = ""; // Traverse the string and // check if there is a digit for (int i = 0; i < str.Length; i++) { char c = str[i]; // If character is a digit, // add it to the string digits if (c >= 48 && c <= 57) { digits += c; } // Otherwise, add it to the // string nonNumericCharacter else { nonNumericCharacter += c; } } // Append both the strings digits += nonNumericCharacter; // Print the string Console.WriteLine(digits); } // Driver Code static public void Main () { // Given String str string str = "GeeksforGeeks123"; moveAllDigitAtBeginning(str); } } // this code is contributed by Pushpesh Raj. JavaScript <script> // JavaScript program for the above approach // Function to move all the digit // to the beginning of the string function moveAllDigitAtBeginning(str) { // Calculate the string length var len = str.length; // Stores the digits var digits = []; // Stores the non-numeric character var nonNumericCharacter = []; // Traverse the string and // check if there is a digit var temp = str.split(""); for(const c of temp) { // If character is a digit, // add it to the string digits if (c.charCodeAt(0) >= 48 && c.charCodeAt(0) <= 57) { digits.push(c); } // Otherwise, add it to the // string nonNumericCharacter else { nonNumericCharacter.push(c); } } // Append both the strings digits.push(nonNumericCharacter.join("")); // Print the string document.write(digits.join("") + " "); } // Driver Code // Given String str var str = "GeeksforGeeks123"; moveAllDigitAtBeginning(str); // This code is contributed by rdtank </script> Output: 123GeeksforGeeks Time Complexity: O(N)Auxiliary Space: O(1) Regular Expression based Approach: The given problem can also be solved using Regular Expression and replace all non-numeric characters with the empty string (“ “) that give you all numbers and replace all digits with the empty string (“ “) that gives you all non-numeric characters. In the end, concatenate the string and print the result. Below is the implementation of the above approach: C++ // C++ program for the above approach #include <iostream> #include <string> #include <regex> using namespace std; // Function to move all the digit // at the beginning of the string void moveAllDigitAtBeginning(string str) { // Replace all the non-numeric // characters with " " and // replace all digits with " " string moveAllDigit = regex_replace(str, regex("\\D+"), "") + regex_replace(str, regex("\\d"), ""); // Print the string cout << moveAllDigit; } // Driver Code int main() { // Given String str string str = "GeeksforGeeks1234"; moveAllDigitAtBeginning(str); return 0; } // This code is contributed by akashish__ Java // Java program for the above approach class GFG { // Function to move all the digit // at the beginning of the string static void moveAllDigitAtBeginning( String str) { // Replace all the non-numeric // characters with " " and // replace all digits with " " String moveAllDigit = str.replaceAll("\\D+", "") + str.replaceAll("\\d+", ""); // Print the string System.out.println(moveAllDigit); } // Driver Code public static void main(String args[]) { // Given String str String str = "GeeksforGeeks1234"; moveAllDigitAtBeginning(str); } } Python3 import re # Function to move all the digit # at the beginning of the string def moveAllDigitAtBeginning(str): # Replace all the non-numeric # characters with "" and # replace all digits with "" moveAllDigit = re.sub(r'\D+',"", str) + re.sub(r'\d+',"", str) # Print the string print(moveAllDigit) # Driver Code if __name__ == "__main__": # Given String str str = "GeeksforGeeks1234" moveAllDigitAtBeginning(str) # This code is contributed by divyansh2212 C# // C# program for the above approach using System; using System.Text.RegularExpressions; public class GFG { // Function to move all the digit // at the beginning of the string static void moveAllDigitAtBeginning( String str) { // Replace all the non-numeric // characters with " " and // replace all digits with " " String moveAllDigit = Regex.Replace(str, "\\D+", "") +Regex.Replace(str, "\\d", ""); // Print the string Console.WriteLine(moveAllDigit); } // Driver Code public static void Main(String []args) { // Given String str String str = "GeeksforGeeks1234"; moveAllDigitAtBeginning(str); } } // This code is contributed by 29AjayKumar JavaScript // Function to move all the digit // at the beginning of the string function moveAllDigitAtBeginning(str) { // Replace all the non-numeric // characters with "" and // replace all digits with "" let moveAllDigit = str.replace(/\D+/g, "") + str.replace(/\d+/g, ""); // Print the string console.log(moveAllDigit); } // Driver Code let str = "GeeksforGeeks1234"; moveAllDigitAtBeginning(str); // contributed by akashish__ Output: 1234GeeksforGeeks Time Complexity: O(N)Auxiliary Space: O(1) Comment More infoAdvertise with us P prashant_srivastava Follow Improve Article Tags : Strings Pattern Searching Technical Scripter DSA Technical Scripter 2020 regular-expression +2 More Practice Tags : Pattern SearchingStrings Similar Reads Basics & PrerequisitesLogic Building ProblemsLogic building is about creating clear, step-by-step methods to solve problems using simple rules and principles. It’s the heart of coding, enabling programmers to think, reason, and arrive at smart solutions just like we do.Here are some tips for improving your programming logic: Understand the pro 2 min read Analysis of AlgorithmsAnalysis of Algorithms is a fundamental aspect of computer science that involves evaluating performance of algorithms and programs. Efficiency is measured in terms of time and space.BasicsWhy is Analysis Important?Order of GrowthAsymptotic Analysis Worst, Average and Best Cases Asymptotic NotationsB 1 min read Data StructuresArray Data StructureIn this article, we introduce array, implementation in different popular languages, its basic operations and commonly seen problems / interview questions. An array stores items (in case of C/C++ and Java Primitive Arrays) or their references (in case of Python, JS, Java Non-Primitive) at contiguous 3 min read String in Data StructureA string is a sequence of characters. The following facts make string an interesting data structure.Small set of elements. Unlike normal array, strings typically have smaller set of items. For example, lowercase English alphabet has only 26 characters. ASCII has only 256 characters.Strings are immut 2 min read Hashing in Data StructureHashing is a technique used in data structures that efficiently stores and retrieves data in a way that allows for quick access. Hashing involves mapping data to a specific index in a hash table (an array of items) using a hash function. It enables fast retrieval of information based on its key. The 2 min read Linked List Data StructureA linked list is a fundamental data structure in computer science. It mainly allows efficient insertion and deletion operations compared to arrays. Like arrays, it is also used to implement other data structures like stack, queue and deque. Here’s the comparison of Linked List vs Arrays Linked List: 2 min read Stack Data StructureA Stack is a linear data structure that follows a particular order in which the operations are performed. The order may be LIFO(Last In First Out) or FILO(First In Last Out). LIFO implies that the element that is inserted last, comes out first and FILO implies that the element that is inserted first 2 min read Queue Data StructureA Queue Data Structure is a fundamental concept in computer science used for storing and managing data in a specific order. It follows the principle of "First in, First out" (FIFO), where the first element added to the queue is the first one to be removed. It is used as a buffer in computer systems 2 min read Tree Data StructureTree Data Structure is a non-linear data structure in which a collection of elements known as nodes are connected to each other via edges such that there exists exactly one path between any two nodes. Types of TreeBinary Tree : Every node has at most two childrenTernary Tree : Every node has at most 4 min read Graph Data StructureGraph Data Structure is a collection of nodes connected by edges. It's used to represent relationships between different entities. If you are looking for topic-wise list of problems on different topics like DFS, BFS, Topological Sort, Shortest Path, etc., please refer to Graph Algorithms. Basics of 3 min read Trie Data StructureThe Trie data structure is a tree-like structure used for storing a dynamic set of strings. It allows for efficient retrieval and storage of keys, making it highly effective in handling large datasets. Trie supports operations such as insertion, search, deletion of keys, and prefix searches. In this 15+ min read AlgorithmsSearching AlgorithmsSearching algorithms are essential tools in computer science used to locate specific items within a collection of data. In this tutorial, we are mainly going to focus upon searching in an array. When we search an item in an array, there are two most common algorithms used based on the type of input 2 min read Sorting AlgorithmsA Sorting Algorithm is used to rearrange a given array or list of elements in an order. For example, a given array [10, 20, 5, 2] becomes [2, 5, 10, 20] after sorting in increasing order and becomes [20, 10, 5, 2] after sorting in decreasing order. There exist different sorting algorithms for differ 3 min read Introduction to RecursionThe process in which a function calls itself directly or indirectly is called recursion and the corresponding function is called a recursive function. A recursive algorithm takes one step toward solution and then recursively call itself to further move. The algorithm stops once we reach the solution 14 min read Greedy AlgorithmsGreedy algorithms are a class of algorithms that make locally optimal choices at each step with the hope of finding a global optimum solution. At every step of the algorithm, we make a choice that looks the best at the moment. To make the choice, we sometimes sort the array so that we can always get 3 min read Graph AlgorithmsGraph is a non-linear data structure like tree data structure. The limitation of tree is, it can only represent hierarchical data. For situations where nodes or vertices are randomly connected with each other other, we use Graph. Example situations where we use graph data structure are, a social net 3 min read Dynamic Programming or DPDynamic Programming is an algorithmic technique with the following properties.It is mainly an optimization over plain recursion. Wherever we see a recursive solution that has repeated calls for the same inputs, we can optimize it using Dynamic Programming. The idea is to simply store the results of 3 min read Bitwise AlgorithmsBitwise algorithms in Data Structures and Algorithms (DSA) involve manipulating individual bits of binary representations of numbers to perform operations efficiently. These algorithms utilize bitwise operators like AND, OR, XOR, NOT, Left Shift, and Right Shift.BasicsIntroduction to Bitwise Algorit 4 min read AdvancedSegment TreeSegment Tree is a data structure that allows efficient querying and updating of intervals or segments of an array. It is particularly useful for problems involving range queries, such as finding the sum, minimum, maximum, or any other operation over a specific range of elements in an array. The tree 3 min read Pattern SearchingPattern searching algorithms are essential tools in computer science and data processing. These algorithms are designed to efficiently find a particular pattern within a larger set of data. Patten SearchingImportant Pattern Searching Algorithms:Naive String Matching : A Simple Algorithm that works i 2 min read GeometryGeometry is a branch of mathematics that studies the properties, measurements, and relationships of points, lines, angles, surfaces, and solids. From basic lines and angles to complex structures, it helps us understand the world around us.Geometry for Students and BeginnersThis section covers key br 2 min read Interview PreparationInterview Corner: All Resources To Crack Any Tech InterviewThis article serves as your one-stop guide to interview preparation, designed to help you succeed across different experience levels and company expectations. Here is what you should expect in a Tech Interview, please remember the following points:Tech Interview Preparation does not have any fixed s 3 min read GfG160 - 160 Days of Problem SolvingAre you preparing for technical interviews and would like to be well-structured to improve your problem-solving skills? Well, we have good news for you! GeeksforGeeks proudly presents GfG160, a 160-day coding challenge starting on 15th November 2024. In this event, we will provide daily coding probl 3 min read Practice ProblemGeeksforGeeks Practice - Leading Online Coding PlatformGeeksforGeeks Practice is an online coding platform designed to help developers and students practice coding online and sharpen their programming skills with the following features. GfG 160: This consists of most popular interview problems organized topic wise and difficulty with with well written e 6 min read Problem of The Day - Develop the Habit of CodingDo you find it difficult to develop a habit of Coding? If yes, then we have a most effective solution for you - all you geeks need to do is solve one programming problem each day without any break, and BOOM, the results will surprise you! Let us tell you how:Suppose you commit to improve yourself an 5 min read Like