Question

js 编程问题，恳求帮助

各位大佬，谁能帮我做下这个题，十分感谢！！

Answer 1

var val = '';
for (var key in obj){
if (obj[key]){
val += key+' ';
}}

Answer 2

var classes = {
item1:true,
item2:false,
item3:true
}
function getClasses(obj){
var className;
for(var i in obj) {
if(obj[i]){
alert(i)
}
}
};
getClasses(classes);