Kotlin For Loop

Kotlin For Loop

Kotlin For loop is used to execute a block of code for each element in a given collection.

Syntax

The syntax of a For loop is

for (item in collection) {
  // body
}

where

• for is keyword.
• ( is the syntax to define the start of condition.
• item is the current item from the collection.
• in is keyword.
• collection is a sequence of items, like an array.
• ) is the syntax to define the end of condition.
• { denotes the start of the For loop body.
• } denotes the end of the For loop body.

Between curly braces, you can write the body of the For loop.

Examples

1. Print elements of a string array

In the following program, we take an array of strings in fruits, and use For loop to iterate over the array, and print the elements.

Kotlin Program

fun main(args: Array<String>) {
    val fruits = arrayOf("apple", "banana", "cherry")
    for (fruit in fruits) {
        println(fruit)
    }
}

Output

apple
banana
cherry

2. Iterate over elements of an integer array

In the following program, we take an integer array in variable nums, and use For loop to print the square of each integer value to output.

Kotlin Program

fun main(args: Array<String>) {
    val nums = arrayOf(1, 2, 3, 4, 5)
    for (num in nums) {
        println(num * num)
    }
}

Output

1
4
9
16
25