数组去重、数组排序、乱序等函数实现
var arr = [1,21,42,63,8,2,8,2,1,3,4,5,6,7];
var Newarr=[];
var NFarr=[];
for(var i=0;i<arr.length;i++){
if(Newarr.indexOf(arr[i])==-1){
Newarr.push(arr[i])
}
}
console.log("数组去重",Newarr)
Newarr.sort(function(a,b){
return a-b;
})
console.log("数组排序",Newarr)
Newarr.sort(function(a,b){
return Math.random>0.5?-1:1;
})
console.log("数组乱序",Newarr)
声明一个函数,参数数组,返回元素小于20的数组。
var arr = [1,21,42,63,8,2,8,2,1,3,4,5,6,7];
function doArrFnc(Objarr) {
var ObjNewarr = [];
for (var i = 0; i < Objarr.length; i++) {
if (Objarr[i] < 20) {
ObjNewarr.push(Objarr[i]);
}
}
return ObjNewarr;
}
var ObjNewarr =doArrFnc(arr);
console.log("小于20数组:" + ObjNewarr);
数组首部增加元素,首部删除元素,尾部增加元素,尾部删除元素
var arr = [1,21,42,63,8,2,8,2,1,3,4,5,6,7];
arr.unshift('Tou');
console.log("首部增加元素:" + arr);
arr.shift();
console.log("首部删除元素:" + arr);
arr.push('wei');
console.log("尾部增加元素:" + arr);
arr.pop();
console.log("尾部删除元素:" + arr);
splice方法的用途
var arr = [1,21,42,63,8,2,8,2,1,3,4,5,6,7];
arr.splice(1, 2);
console.log("删除第二个元素:" + ObjNewarr);
访问属性值
var obj = {name:{age:[{one:19},{two:66,school:'WWW'}]}};
console.log(obj.name.age[1].school);