Kotlin foreach method explained with code examples

Kotlin has a forEach() method that you can use to loop over an Array type variable.

To use it, just call the .forEach method on the variable with Array data type.

Here’s an example of calling the method on an Array of String type:

val nameArr: Array<String> = arrayOf("Jack", "John", "Dan" )

nameArr.forEach {
    println("name value = $it")
}

// name value = Jack
// name value = John
// name value = Dan

The forEach method doesn’t require you to write parentheses and add the name for each iteration of the value.

The current value of the array can be obtained using the it keyword, which is returned implicitly by the forEach method.

Finally, the forEach method can be used in any type of Kotlin Array class (Int, Boolean, Char, etc.)

You can see some example code down below:

val numberArr: Array<Int> = arrayOf(10, 20, 30)

numberArr.forEach {
    println("number value = $it")
}

number value = 10
number value = 20
number value = 30

val charArr: Array<Char> = arrayOf('A', 'B', 'C')

charArr.forEach {
    println("char value = $it")
}

// char value = A
// char value = B
// char value = C

When calling the method, please make sure that you’re using a capital E as in forEach and not foreach.

Otherwise, you’ll get the Kotlin unresolved reference error thrown in compile time.

Now you’ve learned how the forEach method works in Kotlin. Well done! 👍