Indexed Access Operator [, ] in Kotlin

Definition

• This operator replaces the “.get” method of lists and maps in Java.
• The syntax of this operator is similar to that of obtaining a value from an array in Java.
• The value at a position in a list can be obtained just by mentioning the index of the value like “variable[index]”
• The value for a key in a map can be obtained just by mentioning the index of the value like “variable[key]“

Syntax

1. Usage in List

variable_name[index]

For example,

//Assigning the value of the item at 5th position of the list to a variable named value
var value = list[5]

2. Usage in Map

variable_name[key]

For example,

//Assigning the value of the item with key "one" of map to a variable named value
var value = map["one"]

Indexed Access Operator Example Program in Kotlin

//Indexed Access Operator Example Program in Kotlin
//Operator Kotlin Programs, Basic Kotlin Program
fun main(args: Array<String>) {
    
    //Indexed Access operator usage in a list
    val nameList = listOf("Ramesh","Suresh","Dinesh")
    println("The nameList is : $nameList" )
    println("Printing the 0th item of the nameList : ${nameList[0]}" )

    //Indexed Access operator usage in a map
    val nameMap = mapOf(1 to "Sheela",2 to "Leela", 3 to "Maala")
    println("The nameMap is : $nameMap" )
    println("Printing the item of the nameMap with key '2' : ${nameMap[2]}" )
}

Sample Output

The nameList is : [Ramesh, Suresh, Dinesh]
Printing the 0th item of the nameList : Ramesh
The nameMap is : {1=Sheela, 2=Leela, 3=Maala}
Printing the item of the nameMap with key '2' : Leela

How It Works

This Kotlin program demonstrates Indexed Access Operator [, ]. It first prepares the data it needs, then performs the core operation step by step, and finally prints the output shown in the Sample Output above.

1. Declare the variables that hold the program’s data.
2. Print the final result to the console so you can compare it with the sample output.

Try changing the input values and re-running the program to see how the output changes — this is the fastest way to understand how the logic behaves.