js中如何将一个map类型的key值组成一个数组,循环输出
var map = new Map();
map.set("key1","1")
map.set("key2","2")
map.set("key3","3")
var arr1 = []
arr1 = map.keys();
alert(arr1);
/*
for(var i=0; i<arr1.length; i++){
alert(map.get(arr1));
}
*/
上面写的,连map.length都是 undefined
期望alert结果["key1","key2","key3"]