如何从JSON中的指定键获取值

Question

I have this objects:

{label: "Name1", values: ["el0", "el1"]}
{label: "Name2", values: ["el0", "el1"]}

I need to catch label values from this object and values array. So i do this:

$.each(obj, function(index, value){ 
    if (index === "label"){
        var labels = value;
    }
    // actions with data here
});

If i do my actions outside of if labels var is undefined , can anybody help?

Answer 1

If you're trying to access a property on an object, you don't need the if statement.

objects.forEach(function(object){
    var label = object.label;
    //do stuff with label
});

With regards to your posted code, index will always return an integer value, so it will never equal "label" , and labels will never be given a value. Javascript scopes things according to functions, so the variable labels is accessible anywhere in the callback of the each method.

It's even accessible before it's defined, due to variable hoisting, though the value is undefined.

Answer 2

try this:

var labels = null;
$.each(obj, function(index, value){ 
    if (index === "label"){
        labels = value;
    }
    // actions with data here
    // now you can use "labels" variable anywhere, 
    // because it has a global scope.
});

Answer 3

you need array.push for this i guess

var labels = [];
for (var i in obj)
    labels.push(obj[i].label);
console.log(labels);

Answer 4

insted use $.each, try access the label attribute directly.

var labels = obj['label'];

or

var labels = obj.label;

If what you have is an array. try this.

var labels =[];
$.each(objs, function(i, item){
    labels.push(item.label);
});