javascript变量的全局和局部范围混淆

Question

$http({
    method: 'GET',
    url: '../URL'
}).
success(function(data, status, headers, config) {               
    items = data;
})

if(items > 0){
// do something
}

items is not defined in my case. I wonder I assigned data into items which with no var, so it's a global variable. I also tried declare items = "" in global scope, the success scope doesn't overwrite and assign data into it.

Answer 1

You are doing the manipulation of data obtained after the success callback outside the it, which should not be done.

the below part

if(items > 0){
// do something
}

where you manipulate the data obtained after the callback should be inside the success callback itself. Making the variable global is not the way to achieve it as the code is not executed synchronous way.

so the if condition

if(items > 0){
// do something
}

will be getting executed even before the success callback get triggered. And hence the items variable will not be set by that time.

your code should be like

success(function(data, status, headers, config) {               
    items = data;
    //do your manipulation here
})