Question

How to replace the first occurrence of a substring in a string with Kotlin

Answer 1

fun replaceFirst(input: String, search: String, replace: String): String {
    val index = input.indexOf(search)
    
    return if (index >= 0) {
        val before = input.substring(0, index)
        val after = input.substring(index + search.length)
        before + replace + after
    } else {
        input
    }
}

fun main() {
    val s = "aa bb cc dd ee cc"
    
    val result = replaceFirst(s, "cc", "YY")
    
    println(result)
}

 
  
/*
run:
 
aa bb YY dd ee cc

*/

 

70+ SQL courses for beginners and professionals

Answer 2

fun main() {
    val s = "aa bb cc dd ee cc"
    
    val updatedString = s.replaceFirst("cc", "YY")
    
    println(updatedString) 
}


 
  
/*
run:
 
aa bb YY dd ee cc

*/

 

70+ SQL courses for beginners and professionals