Let’s learn for-each loop in java.
for-each loop in java
for-each loop traverse each element of an array sequentially without using index or counter.
for-each loop or enhanced for loop was introduced in JDK 1.5
NOTE:
- Iterating through characters in a string using for-each loop is forward only and in single step.
- for-each loop is not suitable when you want to modify an array.
- In for-each loop we cannot process two decision making statements at one time like if else statement.
- for-each loop can’t keep track of index.
- for-each loop is basically used to traverse elements in Arrays and Collections.
Here’s the syntax and example on for each loop.
Syntax:
for(<DataType of array><variablename> : <Array to be iterated>) { // code }
Example:
import java.util.*; public class ForEachLoopExample { public static void main(String[] args) { int[] numbers = {2, 4, 6, 8, 10}; // for each loop for(int n : numbers) { System.out.println(n); } } }
Output:
2
4
6
8
10
Disadvantage of for each loop
- can’t use for each loop to remove elements while traversing collections.
- can’t use for each loop to modify given index in an array.
- can’t use for each loop to iterate over different arrays.
Traversing or iterating array using foreach loop
Let’s iterate array using for-each loop.
public class ForEachArrayExample { public static void main(String[] args) { String[] strColors = {"red", "blue", "green", "orange", "violet"}; // using for loop System.out.println("Using conventional for loop: "); for(int a = 0; a < strColors.length; a++) { System.out.println(strColors[a]); } System.out.println("\nUsing foreach loop: "); // using for-each loop for(String str : strColors) { System.out.println(str); } } }
Output:
Using conventional for loop:
red
blue
green
orange
violet
Using foreach loop:
red
blue
green
orange
violet
Also read – ArrayList in java