JavaScript parseInt() Function Method

What is Javascript Parseint()?

The JavaScript parseint() function in JavaScript is used to convert a string to an integer. It takes two arguments: the string to be parsed, and an optional radix (the base of the number system to be used). For example, parseInt(“10”, 10) would return 10, and parseInt(“11”, 2) would return 3. If the radix is not specified, js parseint will use base 10 by default. If the string cannot be parsed as a valid integer, parseInt() will return NaN (Not a Number). 

In addition to the basic usage, parseint in javascript() has a few other features and behaviors that are worth noting:

• If the first character of the string is not a valid numerical character, parseInt() will ignore all leading whitespace and non-numerical characters, and start parsing from the first numerical character it finds. For example, parseInt(” 123abc”) would return 123.
• If the first character of the string is a valid numerical character, but the rest of the string contains non-numerical characters, parseInt() will stop parsing at the first non-numerical character and return the parsed integer up to that point. For example, parseInt(“123abc”) would also return 123.
• If the radix is not in the range of 2-36, parseInt() will use the default radix of 10.
• parseInt() always returns a signed 32-bit integer, which means that if the parsed number is larger than 2^31-1 or smaller than -2^31, the result will be a truncated version of the number.

It’s worth noting that since ES6, javascript parseint has another method parseFloat() which parse a string and returns a floating point number.

Syntax of parseInt() in Javascript

There are two methods to utilise Javascript’s parseInt() function: Without the radix value base of the integer value and another passing a radix value.

Parameters of parseInt() in Javascript

The following parameters of parseInt() in javascript:

1. str: The String data type argument that is to parse as an integer data type value.
2. radix value: Radix value represents the basis of the number in the string that literally is to be parsed.

The following is the syntax of parseInt() in javascript:

parseInt(str)

parseInt(str, radix_value)

The benefits of using ‘parseInt()’ include:

• Improved code readability: By explicitly converting a string to an integer using ‘parseInt()’, it is clear to other developers reading the code that the string is intended to be used as a number.
• Consistency: Using ‘parseInt()’ ensures that the conversion will always be done in the same way, regardless of the browser or environment in which the code is running.
• Error handling: ‘parseInt()’ will return ‘NaN’ (not a number) if the input string cannot be converted to a valid integer. This allows for easy error handling in the code.
• Radix optional parameter: ‘parseInt()’ takes an optional second parameter, radix, which is used to specify the base of the number in the string. This can be useful in certain situations where the base is not known or needs to be specified explicitly.
• Improved performance: Using ‘parseInt()’ to convert a string to an integer can be faster than using other methods such as ‘Number()’ or mathematical operations.
• Support for large numbers: ‘parseInt()’ can handle large numbers that may not be accurately represented by other methods, such as floating-point numbers.
• Compatibility: ‘parseInt()’ is a widely supported function that is available in most modern browsers and JavaScript environments, making it a reliable choice for cross-platform development.
• Easy use: ‘parseInt()’ is a simple and easy-to-use function that requires only a single argument, making it straightforward to integrate into any codebase.
• Handling leading whitespaces: ‘parseInt()’ ignores leading whitespaces in the input string and only converts the numeric characters that are present in the string.
• Handling trailing characters: ‘parseInt()’ stops parsing the input string as soon as it encounters a non-numeric character, it will only return the numeric prefix of the string.

Conclusion:- ‘parseInt()’ is a powerful and versatile function in JavaScript that is used to convert a string to an integer.