Equality Operators (==, !=) and Referential equality Operators...

Definition

• The equality operators are operators that check if the values that are compared are equal. This is similar to the Java equals() method. The equality operators are ”==” and ”!=”
• The referential equality operators are operators that check if the values and the object of the variables that are compared are equal. The referential equality operators are ”===” and ”!==“

Syntax

1. Equality Operators

if(value1 == value2){
	//Block of Code
}
(OR)
if(value1 != value2){
	//Block of Code
}

For example,

var num1 = 5
var num2 = 5
if(num1 == num2){
	//Block of Code
}

2. Referential Equality Operators

//value1 and value2 are of different Object types
if(value1 === value2){
	//Block of Code
}
(OR)
if(value1 !== value2){
	//Block of Code
}

For example,

var num1 : Any = 5
var num2 = 5
if(num1 === num2){
	//Block of Code
}

Equality and Referential Equality Operator Example Program in Kotlin

//Equality and Referential Equality Operator Example Program in Kotlin
//Operator Kotlin Programs, Basic Kotlin Program
fun main(args: Array<String>) {
    var num1 : Any  = 100.2
    var num2 = 100.2
    var num3 = 100
    var num4 : Int = 100

    //Checking Equality of same value and non-mentioned Object type
    if(num1 == num2){
        println("$num1('Any' Data type) and $num2(Inferred Data Type) are equal using Equality Operator")
    }

    //Checking Non-Equality of different values and non-mentioned Object type
    if(num1 != num3){
        println("$num1('Any' Data type) and $num3(Inferred Data Type) are not equal using Non-Equality Operator")
    }

    //Checking Referential Equality of same value and non-mentioned Object type
    if(num3 === num4){
        println("$num3(Inferred Data Type) and $num4('Int' Data Type) are equal using Referential Equality Operator")
    }

    //Checking Referential Non-Equality of same value with boxed Object
    if(num1 !== num2){
        println("$num1('Any' Data Type) and $num2(Inferred Data Type) are not equal using Referential Non-Equality Operator")
    }
}

Sample Output

100.2('Any' Data type) and 100.2(Inferred Data Type) are equal using Equality Operator
100.2('Any' Data type) and 100(Inferred Data Type) are not equal using Non-Equality Operator
100(Inferred Data Type) and 100('Int' Data Type) are equal using Referential Equality Operator
100.2('Any' Data Type) and 100.2(Inferred Data Type) are not equal using Referential Non-Equality Operator

How It Works

This Kotlin program demonstrates Equality Operators (==, !=) and Referential equality Operators… It first prepares the data it needs, then uses conditional logic to decide the result, and finally prints the output shown in the Sample Output above.

1. Declare the variables that hold the program’s data.
2. Use conditional statements to handle the different cases.
3. 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.