Understanding Kotlin Comparison Operators: A Beginner's Guide

Introduction and Lesson Overview

Greetings! Today, we're studying comparison operators in Kotlin, which are vital for decision-making in coding. Through engaging examples with different data types, we'll grasp the power of these operators. Let's begin our exploration!

Understanding Comparison Operators

Imagine a daily competitive event where we judge who is taller or faster. Replace these with "greater," "lesser," "equal," or "not equal," and you've got comparison operators! Kotlin uses six basic ones: Equal to (==) Not equal to (!=) Greater than (>) Less than (<) Greater than or equal to (>=) Less than or equal to (<=) Let's explore these through simple examples: Kotlin val num1 = 5 val num2 = 10 println(num1 == num2) //prints: false, as 5 is not equal to 10 println(num1 != num2) //prints: true, as 5 is not equal to 10 println(num1 > num2) //prints: false, as 5 is not greater than 10 println(num1 < num2) //prints: true, as 5 is less than 10 println(num1 >= num2) //prints: false, as 5 is not greater than or equal to 10 println(num1 <= num2) //prints: true, as 5 is less than or equal to 10 val num1 = 5 val num2 = 10 println(num1 == num2) //prints: false, as 5 is not equal to 10 println(num1 != num2) //prints: true, as 5 is not equal to 10 println(num1 > num2) //prints: false, as 5 is not greater than 10 println(num1 < num2) //prints: true, as 5 is less than 10 println(num1 >= num2) //prints: false, as 5 is not greater than or equal to 10 println(num1 <= num2) //prints: true, as 5 is less than or equal to 10 Comparing 5 and 10 using these operators produces boolean values (true or false).

Applying Comparison Operators on Numbers

Consider two brothers: Harry, who is 12, and Ron, who is 14. We can use age comparison operators to compare their ages: Kotlin val ageHarry = 12 val ageRon = 14 println(ageHarry == ageRon) // prints: false, because Harry and Ron are of different ages println(ageHarry != ageRon) // prints: true, as above println(ageHarry > ageRon) // prints: false, because Harry is not older than Ron println(ageHarry < ageRon) // prints: true, because Harry is younger than Ron println(ageHarry >= ageRon) // prints: false, as Harry is not older or as old as Ron println(ageHarry <= ageRon) // prints: true, as Harry is younger or as old as Ron (in this case, younger) val ageHarry = 12 val ageRon = 14 println(ageHarry == ageRon) // prints: false, because Harry and Ron are of different ages println(ageHarry != ageRon) // prints: true, as above println(ageHarry > ageRon) // prints: false, because Harry is not older than Ron println(ageHarry < ageRon) // prints: true, because Harry is younger than Ron println(ageHarry >= ageRon) // prints: false, as Harry is not older or as old as Ron println(ageHarry <= ageRon) // prints: true, as Harry is younger or as old as Ron (in this case, younger)

Comparison Operators with Booleans

Now, let's compare Boolean variables. Note that == and!= are the operators we use here: Kotlin val isMorning = true val isAfternoon = false println(isMorning == isAfternoon) // prints: false, as true does not equal false println(isMorning != isAfternoon) // prints: true, as true is not equal to false val isMorning = true val isAfternoon = false println(isMorning == isAfternoon) // prints: false, as true does not equal false println(isMorning != isAfternoon) // prints: true, as true is not equal to false

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Kotlin

val num1 = 5
val num2 = 10

println(num1 == num2)  //prints: false, as 5 is not equal to 10
println(num1 != num2)  //prints: true, as 5 is not equal to 10
println(num1 > num2)   //prints: false, as 5 is not greater than 10
println(num1 < num2)   //prints: true, as 5 is less than 10
println(num1 >= num2)  //prints: false, as 5 is not greater than or equal to 10
println(num1 <= num2)  //prints: true, as 5 is less than or equal to 10

Kotlin

val ageHarry = 12
val ageRon = 14

println(ageHarry == ageRon)  // prints: false, because Harry and Ron are of different ages
println(ageHarry != ageRon)  // prints: true, as above
println(ageHarry > ageRon)   // prints: false, because Harry is not older than Ron
println(ageHarry < ageRon)   // prints: true, because Harry is younger than Ron
println(ageHarry >= ageRon)  // prints: false, as Harry is not older or as old as Ron
println(ageHarry <= ageRon)  // prints: true, as Harry is younger or as old as Ron (in this case, younger)

Kotlin

val isMorning = true
val isAfternoon = false

println(isMorning == isAfternoon)  // prints: false, as true does not equal false
println(isMorning != isAfternoon)  // prints: true, as true is not equal to false

Kotlin

val char1 = 'a'
val char2 = 'b'

println(char1 == char2)     // prints: false, because 'a' is not the same as 'b'
println(char1 != char2)     // prints: true, as 'a' and 'b' are different
println(char1 > char2)      // prints: false, as 'a' comes before 'b' in the alphabet
println(char1 < char2)      // prints: true, as above
println(char1 >= char2)     // prints: false, as 'a' is not after or in the same position as 'b'
println(char1 <= char2)     // prints: true, as 'a' is before or in the same position as 'b' (in this case, before)

val string1 = "alpha"
val string2 = "beta"

println(string1 == string2)  //prints: false, because "alpha" and "beta" are different words
println(string1 != string2)  //prints: true, as above
println(string1 > string2)   //prints: false, because "a" comes before "b" in the dictionary
println(string1 < string2)   //prints: true, because "a" comes before "b" in the dictionary
println(string1 >= string2)  //prints: false, because "a" comes before "b" in the dictionary
println(string1 <= string2)  //prints: true, because "a" comes before "b" in the dictionary

val char1 = 'a'
val char2 = 'b'

println(char1 == char2)     // prints: false, because 'a' is not the same as 'b'
println(char1 != char2)     // prints: true, as 'a' and 'b' are different
println(char1 > char2)      // prints: false, as 'a' comes before 'b' in the alphabet
println(char1 < char2)      // prints: true, as above
println(char1 >= char2)     // prints: false, as 'a' is not after or in the same position as 'b'
println(char1 <= char2)     // prints: true, as 'a' is before or in the same position as 'b' (in this case, before)

val string1 = "alpha"
val string2 = "beta"

println(string1 == string2)  //prints: false, because "alpha" and "beta" are different words
println(string1 != string2)  //prints: true, as above
println(string1 > string2)   //prints: false, because "a" comes before "b" in the dictionary
println(string1 < string2)   //prints: true, because "a" comes before "b" in the dictionary
println(string1 >= string2)  //prints: false, because "a" comes before "b" in the dictionary
println(string1 <= string2)  //prints: true, because "a" comes before "b" in the dictionary

Kotlin

val char1 = 'a'
val char2 = 'b'

println(char1 == char2)     // prints: false, because 'a' is not the same as 'b'
println(char1 != char2)     // prints: true, as 'a' and 'b' are different
println(char1 > char2)      // prints: false, as 'a' comes before 'b' in the alphabet
println(char1 < char2)      // prints: true, as above
println(char1 >= char2)     // prints: false, as 'a' is not after or in the same position as 'b'
println(char1 <= char2)     // prints: true, as 'a' is before or in the same position as 'b' (in this case, before)

val string1 = "alpha"
val string2 = "beta"

println(string1 == string2)  //prints: false, because "alpha" and "beta" are different words
println(string1 != string2)  //prints: true, as above
println(string1 > string2)   //prints: false, because "a" comes before "b" in the dictionary
println(string1 < string2)   //prints: true, because "a" comes before "b" in the dictionary
println(string1 >= string2)  //prints: false, because "a" comes before "b" in the dictionary
println(string1 <= string2)  //prints: true, because "a" comes before "b" in the dictionary