What is the eqivalent of String.valueOf() in Kotlin?-CodePudding

What is the equivalent of String.valueOf() in Kotlin? I want to convert the java code in kotlin code.

var count = 0
for(i in 0 until rings.length){
    if(rings.contains("R"  String.valueOf(i)) && rings.contains("G"  String.valueOf(i)) && rings.contains("B"  String.valueOf(i)))
       count  
}
 return count

I checked kotlin documentation, but I don't undertand too much. It's kind of confusing.

CodePudding user response：

How about using Kotlin's string templates "$i"

"R"  String.valueOf(i)

becomes:

"R$i"

CodePudding user response：

String.valueOf(X) converts X object to a string by the call of X.toString() or returns "null" if X is null.

Your code tries to convert i to string and i can't be null, so you can replace it to .toString()

rings.contains("R" i.toString()) && rings.contains("G" i.toString()) && rings.contains("B" i.toString())

Kotlin allows you to concat string with object of any type or null, so the expression can be simplified:

rings.contains("R" i) && rings.contains("G" i) && rings.contains("B" i)

And the other variant is the string interpolation:

rings.contains("R$i") && rings.contains("G$i") && rings.contains("B$i")