javascript - Javascript 解析 int

Question

私がこれを行うとき：

parseInt(39,16)

私はこれを得る：

 57 

2 番目の引数の意味は何ですか?

私はこれを読みました：

radix   Optional. A number (from 2 to 36) that represents the numeral system to be used

しかし、16 という数字で何が得られるでしょうか。

Answer 1

The second argument is the number system you're using - in your case "39" is hexadecimal, because you passed "16" as a second argument.

Please refer to the documentation.

So if you want to get decimal number, use:

parseInt(39, 10);

Answer 2

For example, a radix of 10 indicates to convert from a decimal number, 8 octal, 16 hexadecimal, and so on. For radices above 10, the letters of the alphabet indicate numerals greater than 9. For example, for hexadecimal numbers (base 16), A through F are used.

ParseInt documentation