关于判断字符的一些合集

var arr=[1,1,2,2,3,4,5,6,7,7];
function quchong(brr){
	var num =[brr[0]];
	for(var i=1;i<brr.length;i++){
		if(brr.indexOf(brr[i]) == i){
			num.push(brr[i]);
		}
	
	}
 return num;	
}

console.log(JSON.stringify(quchong(arr)));

var arr=[1,1,2,2,3,4,5,6,7,7];
Array.prototype.quchong=function(){
	var num=[this[0]];
	for(var i=1;i<this.length;i++){
		if (this.indexOf(this[i]) == i){
			num.push(this[i]);
		}
	}
 return num;
}

console.log(JSON.stringify(arr.quchong()));