Java 8 furnishes us with another technique String.chars() which returns an IntStream. The returned IntStream contains a number of portrayals of the characters in the string. Here we get stream1 from myString.chars(). We map the returned IntStream into an item. The stream1.mapToObj() changes over the whole number qualities into their particular person same. Be that as it may, to show and peruse the characters, we want to change over them into an easy to understand character structure.
Table of Contents
Iterate Over the Characters of a String in Java
Given string str of length N, the undertaking is to cross the string and print every one of the characters of the given string.
Input : “GeeksforGeeks” Output : G e e k s f o r G e e k s
Input. : “Coder” Output : C o d e r
Method 1: Naive Approach
The simplest approach to solve this problem is to iterate a loop over the range [0, N – 1], where N denotes the length of the string, using the variable i and print the value of str[i].
Example
- Java
// Java Program to Iterate Over the Characters of a String// Using Naive Approach// Importing classes from respective packagesimport java.io.*;import java.util.*;// Main classclass GFG { // Method 1 // Function to traverse the string and // print the characters of the string static void traverseString(String str) { // Traverse the string for (int i = 0; i < str.length(); i++) { // Print current character System.out.print(str.charAt(i) + " "); } } // Method 2 // Main driver method public static void main(String[] args) { // Custom input string String str = "GeeksforGeeks"; // Calling the Method 1 traverseString(str); }} |
G e e k s f o r G e e k s
Time Complexity: O(N)
Auxiliary Space: O(1)
Method 2: Using String.toCharArray() method
In this approach, we convert string to a character array using String.toCharArray() method. Then iterate the character array using for loop or for-each loop.
Example
- Java
// Java Program to Iterate Over the Characters of a String// Using String.toCharArray() method// Importing classes from respective packagesimport java.io.*;import java.util.*;// Main classclass GFG { // Method 1 // To traverse the string and // print the characters of the string static void traverseString(String str) { char[] ch = str.toCharArray(); // Traverse the character array for (int i = 0; i < ch.length; i++) { // Print current character System.out.print(ch[i] + " "); } } // Method 2 // Main driver method public static void main(String[] args) { // Custom input string String str = "GeeksforGeeks"; // Calling the Method 1 traverseString(str); }} |
G e e k s f o r G e e k s
Time Complexity: O(N)
Auxiliary Space: O(N)
1. Naive solution
public class TestJava {
public static void main(String[] args) {
String str = "w3spoint";
// using simple for-loop
for (int i = 0; i < str.length(); i++) {
System.out.println(str.charAt(i));
}
}
}
|
2. Using String.toCharArray() method
public class TestJava {
public static void main(String[] args) {
String str = "w3spoint";
// convert string to `char[]` array
char[] chars = str.toCharArray();
// iterate over `char[]` array using enhanced for-loop
for (char ch: chars) {
System.out.println(ch);
}
}
}
|
3. Using StringCharacterIterator
import java.text.CharacterIterator;
import java.text.StringCharacterIterator;
public class TestJava {
public static void main(String[] args) {
String str = "w3spoint";
CharacterIterator it = new StringCharacterIterator(str);
while (it.current() != CharacterIterator.DONE)
{
System.out.println(it.current());
it.next();
}
}
}
|
4. Using StringTokenizer
import java.util.StringTokenizer;
public class TestJava {
public static void main(String[] args) {
String str = "w3spoint";
@Deprecated
// if returnDelims is true, use the string itself as a delimiter
StringTokenizer st = new StringTokenizer(str, str, true);
while (st.hasMoreTokens()) {
System.out.println(st.nextToken());
}
}
}
|
5. Using String.Split() method
public class TestJava {
public static void main(String[] args) {
String str = "w3spoint";
String[] arr = str.split("");
for (String ch: arr) {
System.out.println(ch);
}
}
}
|
6. Using String.chars() method
public class TestJava {
public static void main(String[] args) {
String str = "w3spoint";
//1. Implicit boxing into `Stream<Character>`
//1.1. Using method reference
str.chars()
.mapToObj(Character::toChars)
.forEach(System.out::println);
//1.2. Using lambda expressions by casting `int` to `char`
str.chars()
.mapToObj(i -> Character.valueOf((char) i))
.forEach(System.out::println);
str.chars()
.mapToObj(i -> (char) i)
.forEach(System.out::println);
str.chars()
.mapToObj(i -> new StringBuilder().appendCodePoint(i))
.forEach(System.out::println);
//2. Without boxing into `Stream<Character>`
str.chars()
.forEach(i -> System.out.println(Character.toChars(i)));
str.chars()
.forEach(i -> System.out.println((char) i));
str.chars()
.forEach(i -> System.out.println(new StringBuilder()
.appendCodePoint(i)));
}
}
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Also Read: Compare two Strings in Java