Exceptions and Defensive Coding

Safe Parsing

Avoid an exception by using a nullable parsing result.

Safe Parsing

SafeParsing.kt 
fun main() {
    val raw = 
    val parsed = raw.toIntOrNull()
    val value = parsed ?: -1
    val status = if (parsed == null) {
        "fallback"
    } else {
        "parsed"
    }

    println("raw=$raw")
    println("value=$value")
    println("status=$status")
}

fun main() {
    val raw = 
    val parsed = raw.toIntOrNull()
    val value = parsed ?: -1
    val status = if (parsed == null) {
        "fallback"
    } else {
        "parsed"
    }

    println("raw=$raw")
    println("value=$value")
    println("status=$status")
}

fun main() {
    val raw = 
    val parsed = raw.toIntOrNull()
    val value = parsed ?: -1
    val status = if (parsed == null) {
        "fallback"
    } else {
        "parsed"
    }

    println("raw=$raw")
    println("value=$value")
    println("status=$status")
}
safe-parse `toIntOrNull` returns `null` instead of throwing when a string is not a number.