JavaScript 代码段

数字转换

• 十进制和16进制相互转换

let hexNumber = (n).toString(16); // to hex
let decimal = parseInt(hexNumber, 16); // to decimal

• 16进制字符串转换为ACSII

From: Stack Overflow

function hex2a(data) {
    let hex = data.toString();
    let str = '';
    for(let i = 0; i < hex.length; i += 2) {
        str += String.fromCharCode(parseInt(hex.substr(i, 2), 16));
    }

    return str;
}

加密

• sha1 加密

var crypto = require('crypto');
var sha1 = crypto.createHash('sha1');
sha1.update('str').digest('hex');

其它

• padLeft

// ES6

function padLeft(str, len) {
    let val = '0'.repeat(len - str.length) + str;

    return val;
 }

• reverse

function reverse(str) {
    return str.split('').reverse().join('');
}