parseIntparseFloat

parseInt and parseFloat are built-in JavaScript functions used to convert strings into numbers. Both functions attempt to parse a string argument and return a floating-point number or an integer respectively.

The parseInt function parses a string argument and returns an integer of the specified radix (the base in mathematical numeral systems). If the radix is not specified, it defaults to 10. It stops parsing when it encounters a character that is not a valid digit in the specified radix. For example, parseInt("123px") will return 123, while parseInt("px123") will return NaN (Not a Number).

The parseFloat function parses a string argument and returns a floating-point number. It parses until it encounters a character that is not a valid character for a floating-point number. Unlike parseInt, parseFloat always assumes a radix of 10. For instance, parseFloat("3.14") returns 3.14, and parseFloat("3.14abc") also returns 3.14. If the string does not start with a valid number, it returns NaN.

Both functions are useful for extracting numerical data from string representations, but it's important to be aware of their parsing behavior, especially when dealing with strings that may contain non-numeric characters.