js

JS–数组去重

let ary1=[1,2,1,2,1,23,4,1,23,24,4,5,2,3,6,7];
function ff(item) {
var ary=[];
for(var i=0;i<ary1.length;i++){
if(!ary.includes(item[i])){
ary.push(item[i])
}
}
return ary
}
console.log(ff(ary1));

var ary2=ary1.filter(function (item,index) {
return !ary1.slice(0,index).includes(item)
});
console.log(ary2);

for(var i=0;i<ary1.length;i++){
if(ary1.indexOf(ary1[i])==!ary1.lastIndexOf(ary1[i])){
ary1.splice(i,1);
i–;
}
}
console.log(ary1);

Array.prototype.remove=function () {
var obj={},ary=[];
this.forEach(function (item) {
obj[item]=item;
})
for(var key in obj){
ary.push(obj[key])
}
return ary;
}
console.log([1,1,1,2,2,2,3,5,5,5,6,8,8,9].remove());