How it works...

Kotlin uses String’s extension functions such as .toLong() and toLongOrNull() to make things easier. Let’s dive into their implementation.

• For Long, use this:

public inline fun String.toLong(): Long = java.lang.Long.parseLong(this)

As you can see, internally, it also calls the Long.parseLong(string) Java static method, and it is similar to the other data types.

• For Short, it's the following:

public inline fun String.toShort(): Short = java.lang.Short.parseShort(this)

• Use this for Int:

public inline fun String.toInt(): Int = java.lang.Integer.parseInt(this)

• For parsing with Radix, use the following:

public inline fun String.toLong(radix: Int): Long = java.lang.Long.parseLong(this, checkRadix(radix))

The checkRadix method checks whether the given [radix] is valid radix for string to number and number to string conversion.