Skip to content
DeveloperMemos

Converting a String to an Int in Kotlin

Kotlin, String, Int2 min read

Converting a string to an integer in Kotlin is a common operation that developers often need to perform. In this article, we will learn how to convert a string to an integer in Kotlin using two different methods.

First, let's understand what an integer is and why we might need to convert a string to an integer in the first place. An integer is a whole number that can be either positive, negative, or zero. It does not have any decimal points or fractional components. In Kotlin, the data type used to represent integers is called Int.

A string, on the other hand, is a sequence of characters enclosed in double quotes. For example, "Hello World!" is a string. Sometimes, we may have a string that contains a number, but we need to convert it to an integer so that we can perform mathematical operations on it.

In Kotlin, there are two methods that we can use to convert a string to an integer. The first method is to use the toInt() function, which is a built-in function in the Kotlin standard library. The syntax for using this function is as follows:

1val string: String = "123"
2val int: Int = string.toInt()

In this example, we have a string called string that contains the number 123. We use the toInt() function to convert this string to an integer and store the result in a variable called int.

The second method for converting a string to an integer in Kotlin is to use the Integer.parseInt() function. This function is a static method of the Integer class, and it takes a string as an argument and returns an integer. The syntax for using this function is as follows:

1val string: String = "123"
2val int: Int = Integer.parseInt(string)

In this example, we have the same string as before, but we use the Integer.parseInt() function to convert it to an integer and store the result in the int variable.

ExpressVPN

Protect your online privacy and security with ExpressVPN, a reliable and fast VPN service.
Sign up now to get 3 months free!

We earn a commission if you make a purchase, at no additional cost to you.

Both of these methods will successfully convert a string to an integer in Kotlin, but there are a few differences between them. The toInt() function is easier to use because it is a member function of the String class, so you can call it directly on a string without having to use the Integer class. However, the Integer.parseInt() function has the advantage of being able to handle strings that contain decimal points or other non-numeric characters, whereas the toInt() function will only work on strings that contain pure integer values.

In conclusion, converting a string to an integer in Kotlin is a simple task that can be accomplished using the toInt() function or the Integer.parseInt() function. Both of these methods are easy to use and will allow you to perform mathematical operations on strings that contain numbers.