判断数据类型
function type(target) {
let ret = typeof (target);
const TYPE_MAP = {
"[object Array]": "array",
"[object Object]": "object",
"[object Number]": "number",
"[object Boolean]": "boolean",
"[object String]": 'string'
};
if (target === null) {
return 'null';
} else if (ret == "object") {
let str = Object.prototype.toString.call(target);
return TYPE_MAP[str];
} else {
return ret;
}
}
生成指定范围随机数
const RandomNum = (min, max) => {
return Math.floor(Math.random() * (max - min + 1)) + min;
}
数组乱序
function arrScrambling(arr) {
let array = arr;
let index = array.length;
while (index) {
index -= 1;
let randomIndex = Math.floor(Math.random() * index);
let middleware = array[index];
array[index] = array[randomIndex];
array[randomIndex] = middleware
}
return array
}
数组交集
const similarity = (arr1, arr2) => arr1.filter(v => arr2.includes(v));
数组中某元素出现的次数
function countOccurrences(arr, value) {
return arr.reduce((a, v) => v === value ? a + 1 : a + 0, 0);
}
加法
function add(arg1, arg2) {
let r1, r2, m;
try { r1 = arg1.toString().split(".")[1].length } catch (e) { r1 = 0 }
try { r2 = arg2.toString().split(".")[1].length } catch (e) { r2 = 0 }
m = Math.pow(10, Math.max(r1, r2));
return (arg1 * m + arg2 * m) / m
}
减法
function sub(arg1, arg2) {
let r1, r2, m, n;
try { r1 = arg1.toString().split(".")[1].length } catch (e) { r1 = 0 }
try { r2 = arg2.toString().split(".")[1].length } catch (e) { r2 = 0 }
m = Math.pow(10, Math.max(r1, r2));
n = (r1 >= r2) ? r1 : r2;
return Number(((arg1 * m - arg2 * m) / m).toFixed(n));
}
乘法
function mcl(num1, num2) {
let m = 0, s1 = num1.toString(), s2 = num2.toString();
try { m += s1.split(".")[1].length } catch (e) { }
try { m += s2.split(".")[1].length } catch (e) { }
return Number(s1.replace(".", "")) * Number(s2.replace(".", "")) / Math.pow(10, m);
}
除法
function division(num1, num2) {
let t1, t2, r1, r2;
try {
t1 = num1.toString().split('.')[1].length;
} catch (e) {
t1 = 0;
}
try {
t2 = num2.toString().split(".")[1].length;
} catch (e) {
t2 = 0;
}
r1 = Number(num1.toString().replace(".", ""));
r2 = Number(num2.toString().replace(".", ""));
return (r1 / r2) * Math.pow(10, t2 - t1);
}
格式化时间
function formatTime(number, format) {
var formateArr = ['Y', 'M', 'D', 'h', 'm', 's'];
var returnArr = [];
var date = new Date(number * 1000);
returnArr.push(date.getFullYear());
returnArr.push(formatNumber(date.getMonth() + 1));
returnArr.push(formatNumber(date.getDate()));
returnArr.push(formatNumber(date.getHours()));
returnArr.push(formatNumber(date.getMinutes()));
returnArr.push(formatNumber(date.getSeconds()));
for (var i in returnArr) {
format = format.replace(formateArr[i], returnArr[i]);
}
return format;
}