How to reverse String.fromCharCode?

String.fromCharCode(72) gives H. How开发者_高级运维 to get number 72 from char H?

'H'.charCodeAt(0)

Use charCodeAt:

var str = 'H';
var charcode = str.charCodeAt(0);

@Silvio's answer is only true for code points up to 0xFFFF (which in the end is the maximum that String.fromCharCode can output). You can't always assume the length of a character is one:

'