Get key value of dictionary by index in jQuery

问题

I have a javascript dictionary object which has a pre-set keys that are defaulted to 0. Then I need to loop through the elements of this dictionary by index and use the value of the key to set its value. Below is my code to make things easier to understand:

var _map = {
    'severity-normal': 0,
    'severity-minimal': 0,
    'severity-moderate': 0,
    'severity-severe': 0,
    'severity-highly-severe': 0
};

    mapSeverities: function () {
        for (var i = 0; i < _map.length; i++) {
            //get the key value, ex: severity-normal, by index (which would by i)
            var key = //retrieved key value
            _map[key] = this.data(key);
        }
    }

In other words, suppose we're dealing with C#, I want to get the KeyValuePair at a certain index, then access its Key and Value properties.

Any suggestions?

回答1:

For object _map, you should use for .. in.

for (var key in _map) {
  _map[key] = this.data[key];
}

回答2:

You can also use $.each like this

$.each(_map, function(key, value) { 
  // key is the key
  // value is the value
});

Working Fiddle

来源：https://stackoverflow.com/questions/10894484/get-key-value-of-dictionary-by-index-in-jquery