The Role of Radix in the parseInt Function

The parseInt function converts a string to an integer. However, it does not always assume a base-10 numeral system. To specify the desired base, the radix parameter is used.

Understanding Radix

Radix refers to the number of values represented by a single digit. For instance, hexadecimal has a radix of 16, octal has a radix of 8, and binary has a radix of 2.

Why Use Radix?

The need for radix arises when dealing with numbers that are not represented in base-10 notation. For example, if we have a hexadecimal number like "0xFF", we need to specify a radix of 16 to correctly parse it.

Parsing Numbers Without Radix

In certain cases, the parseInt function can infer the radix from the input string. However, this behavior can be unreliable and lead to unexpected results. For instance, numbers starting with "0" in ECMAScript 5 were treated as octal, but later browsers consider them decimal.

Explicit Radix Specification

To avoid ambiguity, it is recommended to explicitly specify the radix when calling parseInt. This ensures that the function interprets the string correctly according to the intended base. For example:

// Parse "0xFF" as hexadecimal
var result = parseInt('0xFF', 16);

// Parse "101" as binary
var result = parseInt('101', 2);

By providing the radix, we ensure that the function accurately represents the numeric value of the input string.