數(shù)組:
面向?qū)ο蟮姆绞絼?chuàng)建:
var arr01 = new Array(1,2,3,"abc");
直接創(chuàng)建:
var arr02 = [1,2,3,"abc"]
alert (arr02.length);
alert(arr02[3]);
var arr03 = [[1,2,3],["a","b","c","d"],[true,false]];
alert(arr03.length);//3
alert(arr03[].length);//3
alert(arr03[1].length);//4
alert(arr03[1][0].length);//a
數(shù)組的常用方法:
var a = [1,2,3,4];
var b = a.join("-");
alert(b) //1-2-3-4
var a = [1,2,3,4];
a.push(5);
alert(a);//1,2,3,4,5
var a = [1,2,3,4];
a.pop();
alert(a);//1,2,3
a.unshift(0);#在最前邊添加數(shù)字
alert(a);//0,1,2,3,4
a.shift(); #刪除最前邊的數(shù)字
alert(a);//2,3,4
var arr2 = ["a","b","c","a"];
var num = arr2.indexof("a"); #返回第一次出現(xiàn)的索引
alert(num)
var arr2 = ["a","b","c","a"];
arr2.splice(2,1); #刪除索引為2的值的數(shù)字
arr2.splice(2,1,"e")#把索引為2 的值刪除并插入e
數(shù)組去重:
var a= [1,2,3,4,5,6,7,8,2,1,5];
var a2 = [];
for (var i = 0;i < a.length; i ++){
if (a.indexof(a[i]) == i){ #判斷是否是第一次出現(xiàn)
a2.push(a[1]);
}
}
字符串處理的方法:
var a =charAT(索引)
var a="Micrisoft Yahei";
var b = a.substring(10,15); //Yahei
(10)
定時器:
var timer = setTimeout(function){
alert("hello");
},3000);
- 清除定時器:
clearTimeout(timer)
setInterval --反復執(zhí)行的定時器
字符串反轉(zhuǎn);
split 字符串轉(zhuǎn)成數(shù)組:
var arr = str.split(' ')
isNaN 判斷是不是數(shù)字