JS JSON Pair Key & Value

问题:

Is this the best way to get the key and value from a JS object:

function jkey(p){for(var k in p){return k;}}
function jval(p){for(var k in p){return p[k];}}

var myobj = {'Name':'Jack'};

alert(jkey(myobj)+' equals '+jval(myobj));

Or is there a more direct or faster way ??

What I need to do is to me able to call the key-name and value seperately. the functions work and return the keyname and value, I just wondered if there was a smaller, faster, better way.

Here's a better example, I want to access the key:value as separate variables i.e {assistant:'XLH'}, key=assistant, val = 'XLH';

I only use this when I know for sure that it is a pair and only returns a single key and value.

formY={
    tab:[
        {
            tabID:'Main',
            fset:[
                    {
                        fsID:'Ec',
                        fields:[
                            {ec_id:'2011-03-002'},
                            {owner:'ECTEST'},
                            {assistant:'XLH'},
                            {ec_date:'14/03/2011'},
                            {ec_status:'Unreleased'},
                            {approval_person:'XYZ'},
                        ]
                    }
                ]
        }
        ]
}

回答1:

It would be better to avoid looping the object twice. You could do this:

function getKeyValue(obj) {
    for(var key in obj) {
        if(obj.hasOwnProperty(key)) {
            return {key: key, value: obj[key]};
        }
    }
}

and call it with:

var kv = getKeyValue(obj);
alert(kv.key + ' equals ' + kv.value);

回答2:

For setting an object from JSON in a single line of code I like using the jQuery's parseJSON method. Just pass in your JSON string and it creates the object for you. Then all you have to do is use your obj.Property to access any value.

var myObj = '{"Name":"Jack"}';
var person = $.parseJSON(myObj);
alert(person.Name);  // alert output is 'Jack'

回答3:

I'm finding your question is a little unclear, but I suspect you are looking for:

var myobj = {'Name':'Jack'};

for(var k in myobj){
    if (myobj.hasOwnProperty(k)) {
        alert(k + ' equals ' + myobj[k]);
    }
}