Number.parseInt()

概述

Number.parseInt() 方法依据指定基数 [ 参数 radix 的值],把字符串 [ 参数 string 的值] 解析成整数。

语法

Number.parseInt(string[, radix])

参数

string

A string starting with an integer. Leading whitespace in this argument is ignored.

radix Optional

An integer between 2 and 36 that represents the radix (the base in mathematical numeral systems) of the string. If outside this range, the function will always return NaN. If 0 or not provided, the radix will be inferred based on string's value. Be careful — this does NOT always default to 10! The description below explains in more detail what happens when radix is not provided.

参数 string:要解析的值。 如果此参数不是字符串,则使用 ToString 抽象操作将其转换为字符串。忽略此参数中的前导空格。 参数 radix:一个介于 2 到 36 之间的整数,代表字符串的基数 (数学数字系统中的基)。小心 - 这并不是默认为 10。

返回值

An integer parsed from the given string.

Or NaN when

  • the radix modulo 2**32 is smaller than 2 or bigger than 36, or
  • the first non-whitespace character cannot be converted to a number.

Note: JavaScript does not have the distinction of "floating point numbers" and "integers" on the language level. parseInt() and parseFloat() only differ in their parsing behavior, but not necessarily their return values. For example, parseInt("42") and parseFloat("42") would return the same value: a Number 42.

从给定字符串中解析的整数。如果基数小于 11,且第一个非空白字符不能转换为数字,则返回 NaN。

描述

这个方法和全局的 parseInt() 函数具有一样的函数功能:

Number.parseInt === parseInt; // true

ECMAScript 2015 添加了这部分 (其目的是对全局变量进行模块化). 请另见 parseInt() 获取更多详情和示例。

Polyfill

if (Number.parseInt === undefined) {
    Number.parseInt = window.parseInt;
}

规范

Specification
ECMAScript Language Specification
# sec-number.parseint

浏览器兼容性

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相关链接