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Java For Loop
Basic For Loop:
The basic for loop in Java is used to iterate over a range of values, executing a block of code multiple times. It consists of three parts: initialization, condition, and increment/decrement.
public class ForLoopExample {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
System.out.println("Iteration: " + i);
}
}
}
Console Output:
Iteration: 0
Iteration: 1
Iteration: 2
Iteration: 3
Iteration: 4
For Loop with Array
Iterating Over an Array:
For loops are commonly used to iterate over arrays, allowing you to access each element by its index.
public class ArrayLoopExample {
public static void main(String[] args) {
int[] numbers = {10, 20, 30, 40, 50};
for (int i = 0; i < numbers.length; i++) {
System.out.println("Element: " + numbers[i]);
}
}
}
Console Output:
Element: 10
Element: 20
Element: 30
Element: 40
Element: 50
Enhanced For Loop
Using Enhanced For Loop:
The enhanced for loop, also known as the for-each loop, simplifies the iteration over arrays and collections by eliminating the need for index management.
public class EnhancedForLoopExample {
public static void main(String[] args) {
String[] fruits = {"Apple", "Banana", "Cherry"};
for (String fruit : fruits) {
System.out.println("Fruit: " + fruit);
}
}
}
Console Output:
Fruit: Apple
Fruit: Banana
Fruit: Cherry
Nested For Loops
Working with Nested Loops:
Nested for loops are used when you need to perform repeated actions within another loop. They are often used for multi-dimensional data structures.
public class NestedLoopExample {
public static void main(String[] args) {
for (int i = 1; i <= 3; i++) {
for (int j = 1; j <= 3; j++) {
System.out.println("i: " + i + ", j: " + j);
}
}
}
}
Console Output:
i: 1, j: 1
i: 1, j: 2
i: 1, j: 3
i: 2, j: 1
i: 2, j: 2
i: 2, j: 3
i: 3, j: 1
i: 3, j: 2
i: 3, j: 3
For Loop with Break
Using Break in For Loop:
The break statement is used to exit a loop prematurely when a specific condition is met.
public class BreakExample {
public static void main(String[] args) {
for (int i = 0; i < 10; i++) {
if (i == 5) {
break;
}
System.out.println("Number: " + i);
}
}
}
Console Output:
Number: 0
Number: 1
Number: 2
Number: 3
Number: 4
For Loop with Continue
Using Continue in For Loop:
The continue statement skips the current iteration of the loop and proceeds to the next iteration.
public class ContinueExample {
public static void main(String[] args) {
for (int i = 0; i < 10; i++) {
if (i % 2 == 0) {
continue;
}
System.out.println("Odd Number: " + i);
}
}
}
Console Output:
Odd Number: 1
Odd Number: 3
Odd Number: 5
Odd Number: 7
Odd Number: 9
For Loop with Decrement
Decrementing in For Loop:
For loops can also decrement the loop variable, which is useful for counting downwards.
public class DecrementLoopExample {
public static void main(String[] args) {
for (int i = 5; i > 0; i--) {
System.out.println("Countdown: " + i);
}
}
}
Console Output:
Countdown: 5
Countdown: 4
Countdown: 3
Countdown: 2
Countdown: 1
For Loop with Multiple Variables
Using Multiple Variables in For Loop:
Java allows the use of multiple variables in a single for loop, which can be useful for iterating over multiple sequences simultaneously.
public class MultiVariableLoopExample {
public static void main(String[] args) {
for (int i = 0, j = 10; i < j; i++, j--) {
System.out.println("i: " + i + ", j: " + j);
}
}
}
Console Output:
i: 0, j: 10
i: 1, j: 9
i: 2, j: 8
i: 3, j: 7
i: 4, j: 6
For Loop with Complex Condition
Complex Conditions in For Loop:
A for loop can have complex conditions that involve multiple logical operators, allowing for more sophisticated iteration control.
public class ComplexConditionExample {
public static void main(String[] args) {
for (int i = 0; i < 10 && i % 2 == 0; i++) {
System.out.println("Even Number: " + i);
}
}
}
Console Output:
Even Number: 0
