In This Article, You Will Learn about Java For Loop.
Java For Loop – Before moving ahead, let’s know a bit about Java while Loop.
Table of Contents
For Loop
For Loop is another loop in Java like a while loop. For Loop is used when we have to iterate over a particular time through a list or group of items and a code block.
Syntax
for (statement 1; statement 2; statement 3) {
// code block to be executed
}
Explanation:
Statement 1 – It executes only one time before the execution of the code block.
Statement 2 – It defines the condition to execute the code block.
Statement 3 – It executes every time after the condition’s code block is executed.
Example: Write the number from 10 to 5 by using for loop.
public class Main {
public static void main(String[] args) {
for (int i = 10; i < 5; i - -) {
System.out.println(i);
}
}
}
In the above example, as per the condition, in each iteration number 1 will be subtracted (i – -) from the current value of i, and this process will keep going on until i = 6.
Step 1: Since i = 10, it is greater than 5 according to the condition defined. Later on, 1 number will be subtracted as per the condition i – – and i = 9.
Above the same condition will keep going on until i = 6 and to the next step when i = 6 will be checked for i < 5, it will be false; therefore loop will break and stop the execution.
Example: Create an Infinite loop with for loop.
public class Main {
public static void main(String[] args) {
for (int i = 5; i < 10; i--) {
System.out.println(i);
}
}
}
In the above example, as per the condition, in each iteration number 1 will be (i – -) from the current value of i and this process will keep going on forever because i = 5 will always be less than i = 10; therefore condition will always be true and the loop will keep continuing the execution the code block.
Example: Write the number from 15 to 5 by using for loop. At intervals of 2 numbers.
public class Main {
public static void main(String[] args) {
for (int i = 15; i > 5; i = i - 2) {
System.out.println(i);
}
}
}
In the above example, as per the condition, in each iteration number 1 will be added (i = i + 2) from the current value of i, and this process will keep going on until i = 5.
Step 1: Since i = 15, it is greater than 5 according to the condition defined. Later on, number 2 will be subtracted as per the condition, and become i = 5.
Above the same condition will keep going on until i = 7 and to the next step when i = 5 will be checked for i > 5, it will be false; therefore loop will break and stop the execution.
Example: Write the number from 10 to 5 by using for loop.
public class Main {
public static void main(String[] args) {
for (int i = 20; i > 11; i = i+2) {
System.out.println(i);
}
}
}
In the above example, as per the condition, in each iteration number 2 will address (i = i+2) from the current value of i, and this process will keep going on forever because i = 11 will always be less than i = 20; therefore condition will always be true and the loop will keep continuing the execution the code block.
For-Each Loop
There is also a “for-each” loop, which is used to loop through elements in an array.
Syntax
for (type variableName : arrayName) {
// code block to be executed
}
Example: Print the list of student’s name by using for-each loop.
public class Main {
public static void main(String[] args) {
String[] names = {"AK", "JK", "PK", "SK"};
for (String i : names) {
System.out.println(i);
}
}
}
If you find anything incorrect in the above-discussed topic and have further questions, please comment below.
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