By Vishal Basumatary in javascript — Mar 25, 2023

Convert string to integer

Converting a string to an integer is a common task in programming. It is often needed when working with user input or data from external sources. There are several ways to do this in different programming languages. Here are some methods to convert a string to an integer in PHP:

Method 1: Using the intval() function

The intval() function in PHP can be used to convert a string to an integer. It takes a string as input and returns an integer. Here is an example:


    $string = "123";
    $integer = intval($string);

In this example, the variable $string contains the string "123". The intval() function is used to convert it to an integer and store it in the variable $integer.

Method 2: Using the (int) type casting operator

The (int) type casting operator can also be used to convert a string to an integer in PHP. It works by simply placing (int) before the string that needs to be converted. Here is an example:


    $string = "123";
    $integer = (int)$string;

In this example, the variable $string contains the string "123". The (int) operator is used to convert it to an integer and store it in the variable $integer.

Method 3: Using the sscanf() function

The sscanf() function in PHP can be used to parse a string and extract values from it. In this case, we can use it to extract an integer from a string. Here is an example:


    $string = "123";
    sscanf($string, "%d", $integer);

In this example, the variable $string contains the string "123". The sscanf() function is used to parse the string and extract an integer. The %d format specifier tells sscanf() to look for an integer in the string. The extracted integer is stored in the variable $integer.

Method 4: Using the filter_var() function

The filter_var() function in PHP can be used to filter and validate data. It can also be used to convert a string to an integer. Here is an example:


    $string = "123";
    $integer = filter_var($string, FILTER_VALIDATE_INT);

In this example, the variable $string contains the string "123". The filter_var() function is used to validate and convert it to an integer. The FILTER_VALIDATE_INT option tells filter_var() to check if the string is a valid integer and return it as an integer. The converted integer is stored in the variable $integer.