1.數組去重
var arr = ['apple','strawberry','banana','pear','apple','orange','orange','strawberry'];
var r = arr.filter(function(element,index,self){
return self.indexOf(element) === index;
});
console.log(r);
2.删除對象屬性
var arr={
a:1,
b:2
};
delete arr.b;
console.log(arr)