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How to convert a string to an integer and vice versa in Kotlin

How to convert a string to an integer and vice versa in Kotlin.

Here's a step-by-step tutorial on how to convert a string to an integer and vice versa in Kotlin.

Converting a String to an Integer​

To convert a string to an integer in Kotlin, you can use the toInt() method. Here's how you can do it:

  1. Create a string variable that holds the string value you want to convert to an integer.
val str = "42"
  1. Convert the string to an integer using the toInt() method.
val intValue = str.toInt()

The toInt() method parses the string and returns its corresponding integer value. If the string cannot be parsed as an integer, a NumberFormatException will be thrown.

val str = "Hello"
val intValue = str.toInt() // Throws NumberFormatException
  1. Use the converted integer value as needed.
println(intValue) // Output: 42

Converting an Integer to a String​

To convert an integer to a string in Kotlin, you can use the toString() method. Here's how you can do it:

  1. Create an integer variable that holds the integer value you want to convert to a string.
val intValue = 42
  1. Convert the integer to a string using the toString() method.
val str = intValue.toString()

The toString() method converts the integer value to its corresponding string representation.

  1. Use the converted string value as needed.
println(str) // Output: "42"

Handling Exceptions​

When converting a string to an integer using toInt(), it's important to handle the NumberFormatException that can occur if the string cannot be parsed as an integer. You can use a try-catch block to handle the exception. Here's an example:

val str = "Hello"

try {
    val intValue = str.toInt()
    println(intValue)
} catch (e: NumberFormatException) {
    println("Invalid input")
}

In this example, if the toInt() method throws a NumberFormatException, the catch block will be executed and "Invalid input" will be printed.

That's it! You now know how to convert a string to an integer and vice versa in Kotlin.