Java Program to Iterate Over Characters in String
Last Updated :
06 Jun, 2021
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Given string str of length N, the task is to traverse the string and print all the characters of the given string using java.
Illustration:
Input : str = “GeeksforGeeks” Output : G e e k s f o r G e e k s
Input : str = "GfG" Output : G f G
Methods:
- Using for loops(Naive approach)
- Using iterators (Optimal approach)
Method 1: Using for loops
The simplest or rather we can say naive approach to solve this problem is to iterate using a for loop by using the variable ‘i’ till the length of the string and then print the value of each character that is present in the string.
Example
- Java
Java
// Java Program to Iterate Over Characters in String // Class 1 // Main class // To iterate over characters class GFG { // Method 1 // To traverse the string and // print the characters of the string static void getChar(String str) { // Traverse the string using for loop for (int i = 0; i < str.length(); i++) { // Printing the current character System.out.print(str.charAt(i)); // Printing a space after each letter System.out.print(" "); } } // Method 2 // Main driver method public static void main(String[] args) { // Creating a String variable to store the string String str = "GeeksforGeeks"; // Calling the getChar method getChar(str); } } |
Output
G e e k s f o r G e e k s
Time complexity is O(N) and space complexity is O(1)
Method 2: Using iterators
The string can be traversed using an iterator. We would be importing CharacterIterator and StringCharacterIterator classes from java.text package
Example:
- Java
Java
// Java Program to Iterate Over Characters in String // Importing input output classes import java.io.*; // Importing CharacterIterator and StringCharacterIterator // classes from java.text package import java.text.CharacterIterator; import java.text.StringCharacterIterator; // Main class // To iterate over characters class GFG { // Method 1 // To traverse the string and // print the characters of the string static void getChar(String str) { // Creating a CharacterIterator variable CharacterIterator itr = new StringCharacterIterator(str); // Iterating using while loop while (itr.current() != CharacterIterator.DONE) { // Print the current character System.out.print(itr.current()); // Print a space after each letter System.out.print(" "); // Getting the next input from the user // using the next() method itr.next(); } } // Method 2 // Main driver method public static void main(String[] args) { // Creating a String variable to store the string String str = "GfG"; // Calling the getChar method getChar(str); } } |
Output
G f G
Time Complexity: O(N) and space complexity is of order O(1)
