For Loop:
In Java, the for loop is a control inflow statement that allows you to repeatedly execute a block of code a specified number of times. It is particularly useful when you already know the number of iterations.
forLoop.java
for (initialization; condition; update) {
// Code to be executed repeatedly
}
initialization - assign value to a variable.
condition - check condition.
update - change the value of variable.
forLoop.java
public class Main {
public static void main(String[] args) {
for (int i = 1; i <= 5; i++) {
System.out.println("Count is: " + i);
}
}
}In this Example:
- Statement-1 shows i=0.
- Statement-2 checks condition, i is less than 5(true), move inside loop and print count.
- Statement-3 will increment i, now i=1. Statement-2 checks condition, i is less than 5(true), move inside loop and print count.
- Statement-3 will increment i, now i=2. Statement-2 checks condition i is less than 5(true), move inside loop and print count.
- Statement-3 will increment i, now i=3. Statement-2 checks condition i is less than 5(true), move inside loop and print count.
- Statement-3 will increment i, now i=4. Statement-2 checks condition i is less than 5(true), move inside loop and print count.
- Statement-3 will increment i, now i=5. Statement-2 checks condition i is less than 5(false), loop will terminate and control moves to next line.
Infinite For Loop:
If you put the double semicolon inside paranthesis, it will become infinite for loop.forLoop.java
public class Main {
public static void main(String[] args) {
for (;;) {
System.out.println("Hi there!");
}
}
}Nested For Loop:
Nested loops are loops within loops. When we have a nested loops then, when outer loop runs one-time, inner loops complete its all iterations. After that control moves to the outer loop. Again, the outer loop runs a second time and inner loop completes its all iterations. This process will continue until the outer loop completes its all iterations.forLoop.java
public class Main {
public static void main(String[] args) {
for (int i = 1; i <= 3; i++) {
System.out.println("Outer: " + i);
for (int j = 1; j <= 3; j++) {
System.out.println("\nInner: " + j);
}
}
}
}For each Loop:
In Java, the "for-each" loop, also known as the enhanced for loop, provides a convenient way to iterate through elements in an array or collection (such as ArrayList, List, Set, or Map) without the need for explicit index-based iteration.forLoop.java
public class Main {
public static void main(String[] args) {
String[] fruits = {"Apple", "Mango", "Banana"};
for (String fruit : fruits) {
System.out.println(fruit);
}
}
}