Kotlin Training Program

Equality check

We check char equality using the equals() function. If not ignoring case, then we can use the equality operator == also. It invokes the equals() function only :

 fun main() {
    println('A'.equals('a')) // false
		// OR
		println('A' == 'a') // false

		println('A'.equals('a', ignoreCase = true)) // true
}
 

Lets implement this function on our own. We can follow the below steps in order to achieve this :

• If not ignoring case, then directly compare code of both the characters
• Else (ignoring case),
  • convert both characters to the same case then
  • compare their codes

 fun Char.equals(other: Char, ignoreCase: Boolean = false): Boolean {
    return if (ignoreCase) {
        // convert both to same case and compare
        lowercaseChar().code == other.lowercaseChar().code
    } else {
        // compare directly
        this.code == other.code
    }
}