为什么Node crypto为同一个字符串返回不同的值？

Question

I am trying to run this program:

var crypto = require('crypto');
var a = crypto.createHash('md5').update('89Zr-J591').digest('hex');
var name = '89Zr−J591';
var b = crypto.createHash('md5').update(name).digest('hex');

console.log(a); //c6281bc77bea86a92df59225357b6b54
console.log(b); //a3853813486b53eca6bf7d2428876161
console.log(a === b); //false

I expect both a and b to be true ... to be the same.

Why is this not the case? Why are they different?

Answer 1

They are not the same string, see the hyphen:

'89Zr-J591'
//   ^ this is U+002D
'89Zr−J591'
//   ^ this is U+2212

% charinfo −-
U+2212 MINUS SIGN [Sm]
U+002D HYPHEN-MINUS [Pd]

In the first example U+002D is used. Which is what you get when pressing minus on your keyboard.

In the second example U+2212 is used.