1.寫(xiě)一個(gè)函數(shù)哭懈，返回從min到max之間的 隨機(jī)整數(shù)灾馒，包括min不包括max
function random(min,max){
var num = Math.random() * (max - min) + min;
return Math.floor(num);
}
var result = random(3,9);
console.log(result);
2.寫(xiě)一個(gè)函數(shù)，生成一個(gè)長(zhǎng)度為 n 的隨機(jī)字符串遣总，字符串字符的取值范圍包括0到9睬罗，a到 z，A到
function getRandStr(len){
var str = "";
var dict = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
for(var i = 0; i < len; i++){
var index = Math.floor(Math.random() * dict.length);
str += dict[index];
}
return str;
}
var str = getRandStr(10); // 0a3iJiRZap
3.寫(xiě)一個(gè)函數(shù)旭斥，生成一個(gè)隨機(jī) IP 地址容达，一個(gè)合法的 IP 地址為 0.0.0.0~255.255.255.255
function adr(){
var numIP = [];
for(var i = 0; i < 4; i++){
var num = Math.floor(Math.random() * 255);
numIP.push(num);
}
var strIP = numIP.join(".");
return strIP;
}
adr();
4.寫(xiě)一個(gè)函數(shù)，生成一個(gè)隨機(jī)顏色字符串垂券，合法的顏色為#000000~ #ffffff
function getRandColor(){
var dict = "0123456789abcdefghijklmnopqrstuvwxyz";
var color = "#";
for(var i = 0; i < 6; i++){
var index = Math.floor(Math.random() * dict.length);
color += dict[index];
}
return color;
}
getRandColor();
5.實(shí)現(xiàn)一個(gè)flatten函數(shù)花盐，將一個(gè)嵌套多層的數(shù)組 array（數(shù)組） (嵌套可以是任何層數(shù))轉(zhuǎn)換為只有一層的數(shù)組，數(shù)組中元素僅基本類型的元素或數(shù)組菇爪，不存在循環(huán)引用的情況算芯。
var newArr = [];
function flatten(arr){
for(var i = 0; i < arr.length; i++){
if(Array.isArray(arr[i])){
flatten(arr[i]);
}else{
newArr.push(arr[i]);
}
}
return newArr;
}
var arr = [1, [2], [3, [[4]]]];
flatten(arr);
6.實(shí)現(xiàn)一個(gè)reduce函數(shù)，作用和原生的reduce類似
function reduce(arr,callback,intialValue){
var accumulator = intialValue;
var startIndex = 0;
if(typeof intialValue == "undefined"){
accumulator = arr[0];
startIndex = 1;
}
for(var i = startIndex; i < arr.length; i++){
accumulator = callback(accumulator,arr[i],i,arr)
}
return accumulator;
}
reduce([1, 2, 3], function (a, b, c, d) {
return a + b
}, 100)
7.寫(xiě)一個(gè)函數(shù)getChIntv凳宙，獲取從當(dāng)前時(shí)間到指定日期的間隔時(shí)間
function getInterval(fixationTime){
var nowTime = Date.now();
var endTime = Date.parse(fixationTime);
var interval = Math.abs(nowTime - endTime);
var intervalStr = new Date(interval);
var year = intervalStr.getFullYear() - 1970;
var month = intervalStr.getMonth();
var date = intervalStr.getDate();
var hour = intervalStr.getHours();
var minute = intervalStr.getMinutes();
var second = intervalStr.getSeconds();
var text = "時(shí)間間隔："+ year + "年" + month + "月" + date + "天"
+ hour + "小時(shí)" + minute + "分" + second + "秒"
return text;
}
var str = getInterval("2017-02-08 10:30:24");
console.log(str);
8.寫(xiě)一個(gè)函數(shù)也祠，參數(shù)為時(shí)間對(duì)象毫秒數(shù)的字符串格式，返回值為字符串近速。假設(shè)參數(shù)為時(shí)間對(duì)象毫秒數(shù)t诈嘿，根據(jù)t的時(shí)間分別返回如下字符串:
- 剛剛（ t 距當(dāng)前時(shí)間不到1分鐘時(shí)間間隔）
- 3分鐘前 (t距當(dāng)前時(shí)間大于等于1分鐘，小于1小時(shí))
- 8小時(shí)前 (t 距離當(dāng)前時(shí)間大于等于1小時(shí)削葱，小于24小時(shí))
- 3天前 (t 距離當(dāng)前時(shí)間大于等于24小時(shí)奖亚，小于30天)
- 2個(gè)月前 (t 距離當(dāng)前時(shí)間大于等于30天小于12個(gè)月)
- 8年前 (t 距離當(dāng)前時(shí)間大于等于12個(gè)月)
function friendlyDate(t){
if(typeof t !== "number" || isNaN(NaN)){
return "參數(shù)非法"
}
var nowTime = Date.now();
var interval = nowTime - t;
var oneMinute = 1*60*1000;
var oneHour = 1*60*60*1000;
var oneDay = 24*60*60*1000;
var oneMonth = 30*24*60*60*1000;
var oneYear = 12*30*24*60*60*1000;
var text;
if(interval < 0){
text = "傳入的是未來(lái)時(shí)間"
}else if(interval < oneMinute){
text = "剛剛"
}else if(interval >= oneMinute && interval < oneHour){
text = "3分鐘前"
}else if(interval >= oneHour && interval < oneDay){
text = "8小時(shí)前"
}else if(interval >= oneDay && interval < oneMonth){
text = "3天前"
}else if(interval >= oneMonth && interval < oneYear){
text = "2個(gè)月前"
}else if(interval > oneYear){
text = "8年前"
}
return text;
}
//var str = friendlyDate(Date.parse('2018-09-03T03:25:00'));
