[removed] How can I get all the keys and values of an object that begin with a specific string?

Question

I am trying to get all the keys and values of an object that begin with imageIds.

My object appears as the following:

{
    title: \'fsd         


        

Answer 1

One also needs to use hasOwnProperty in conjunction with the for-in loop (not mentioned in most current previous answers).
Reason is that the for-in loop will also go over the methods/properties that an object would inherit from the proto-type chain (should someone or some library have added custom stuff).

So you are looking for something simple and reliable like this:

function fetch(obj, str){
    var key, results = [];
    for(key in obj) obj.hasOwnProperty(key) 
                 && key.indexOf(str) === 0 
                 && results.push([ key, obj[key] ]);
    return results;
}

_{Note: you could also name this function 'getAllKeysAndValuesStartingWith' (or gakavsw should you work for the army haha).}

Usage:

fetch(object, string) returns a simple (to loop over) array with found results,
so var my_results = fetch(testObj, 'imageId'); would give the following output:

[ //array of arrays
  ['imageIds', '/uploads/tmp/image-3.png']
, ['imageIdsZh', '']                               /* 
, [key, value]           and more if it finds them */
]

Working jsfiddle here.

Naturally one could also push just the values: results.push(obj[key])
I would recommend against returning an object ( (results[key]=obj[key]) ) since the array is easier to work with in this case.

Hope this helps!