Date

<script> //1.Date對象var d1 = new Date(); //Thu May 02 2019 14:27:19 GMT+0800 (中國標準時間) console.log(d1); //轉成2019/5/2 下午2:27:19 console.log(d1.toLocaleString());//距離1900年經過年數console.log(d1.getYear());//119 //獲取當前紀年console.log(d1.getFullYear());//2019 //獲取一年中當前月份console.log(d1.getMonth()); //4, 0-11//獲取一個月中的日期 console.log(d1.getDate());//時 console.log(d1.getHours()); //分 console.log(d1.getMinutes()); //秒 console.log(d1.getSeconds());//設置月份時，記得值為0-11var d2 = new Date(2012,11,12,12,12,12);console.log(d2.toLocaleString());//2012/12/12 下午12:12:12//可以創建一個距離1970年經過的毫秒數var d3 = new Date(1528980372222);console.log(d3.toLocaleString()) </script>

Math

<script >console.log(Math.random()) // [0,1) 隨機數console.log(Math.abs(-5)) //求取絕對值 console.log(Math.round(4.5)); //四舍五入 console.log(Math.ceil(3.1)); //天花板 console.log(Math.floor(3.9)); //地板 console.log(Math.pow(2,20)); //x的y次冪 console.log(Math.PI); //圓周率 </script>

String

<script type="application/javascript">//var str = new String("aabbcc");var str2 = "aabdcbc";//console.log(str); console.log(str2);//轉化大小寫console.log(str2.toUpperCase()); //大寫console.log(str2.toLowerCase()); //小寫//返回指定索引處的字母console.log(str2.charAt(3));//返回指定字母首次出現的索引console.log(str2.indexOf("b"));//返回指定字母最后一次出現的索引console.log(str2.lastIndexOf("b"));//截取子字符串，從x位置截取y個字符console.log(str2.substr(2,3));//截取子字符串，從x位置截到y位置console.log(str2.substring(2,3));//字符串length屬性表示字符的個數 console.log(str2.length)</script>

Object

<script type="application/javascript">//1.在js中，我們可以使用Object對象來表述一個人var obj = new Object();//2.在js中，對象有個特點：屬性可以動態的添加//添加屬性obj.name = "laowang";//修改屬性的值obj.name = "laoma";//刪除屬性delete obj.name;function factory(name,age){var obj = new Object();obj.name = name;obj.age = age;return obj;}var per1 = factory("laowang",30);console.log(per1.name);var c1 = factory("benz",3);console.log(c1.name);//封裝的人“類”function Person(name,age){this.name = name;this.age = age;}var p1 = new Person("zhangsan",20);console.log(p1.name);console.log(p1.age);var p2 = new Person("喬峰",25);console.log(p2.name);console.log(p2.age);p2.skill = "降龍十八掌";console.log(p1.skill);console.log(p2.skill);//為所有對象都添加屬性Person.prototype.money = 8888;Person.prototype.like = ["吃飯","睡覺","打豆豆"];Person.prototype.eat = function(){alert("吃飯了，好開心！");}console.log(p1.money);console.log(p2.money);p1.like.push("寫Java");console.log(p1.like);console.log(p2.like);p1.money = 88888;console.log(p1.money);console.log(p2.money);function Student(){this.sno = Math.random();}Student.prototype = new Person("lisi",8);var s1 = new Student();console.log(s1.name);console.log(s1.age);console.log(s1.sno);console.log(s1.money);console.log(s1.like)</script>

?

轉載于:https://www.cnblogs.com/aknife/p/10805153.html

總結

以上是生活随笔為你收集整理的JS 04 Date_Math_String_Object的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。