Javascript对象自动排序

Question

// mechanics
MECHANICS_ISOLATION : 1,
MECHANICS_NA : 2,
MECHANICS_COMPOUND : 3,

// mechanics
Exercise.mechanics = {};
Exercise.mechanics[Exercise.MECHANICS_COMPOUND] = 'Compound';
Exercise.mechanics[Exercise.MECHANICS_ISOLATION] = 'Isolation';
Exercise.mechanics[Exercise.MECHANICS_NA] = 'N/A';

When I loop through Exercise.mechanics , the keys come out sorted. How can I get the unsorted keys to loop through?

Thanks!

Answer 1

Keys in a hashmap is not reliable. Give you keys an order. For example, put your keys into an array and iterate the keys.

var keys = [MECHANICS_ISOLATION, MECHANICS_NA, MECHANICS_COMPOUND];
for (var i = 0; i < keys.length; i++) {
    console.log(Exercise.mechanics[keys[i]]);
}

Answer 2

What is the order you expect? I get them un-ordered in Fx and IE

3:Compound
1:Isolation
2:N/A 

using this code DEMO

Exercise = {
// mechanics
MECHANICS_ISOLATION : 1,
MECHANICS_NA : 2,
MECHANICS_COMPOUND : 3,
    }

// mechanics
Exercise.mechanics = {};
Exercise.mechanics[Exercise.MECHANICS_COMPOUND] = 'Compound';
Exercise.mechanics[Exercise.MECHANICS_ISOLATION] = 'Isolation';
Exercise.mechanics[Exercise.MECHANICS_NA] = 'N/A';

for (ex in Exercise.mechanics) document.write("<hr>"+ex+":"+Exercise.mechanics[ex])