How do I insert a key value pair at a specific point in a key/value array in jquery/javascript?

Question

Hope someone can help in jquery if I have a key value array object

    var myArray= {};
    myArray['key1'] = 'value1';
    myArray['key2'] = 'value2';
    myArray['key3'] = 'value3';
    myArray['key5'] = 'value5';
    myArray['key6'] = 'value6';

how would I insert another key value pair at a specific point? eg myArray['key4'] = 'value4'; between (or after) key2 and (or before) key3?

Thank you

Answer 1

There is no guaranteed order in ECMAscript Objects , hence, there is no way to insert a new key/value pair at a certain point.

Use an Array instead.

var arr = ['value1', 'value2', 'value3', 'value4', 'value5', 'value6'];

arr.splice(2, 0, 'new value');

console.log( arr ); // ['value1', 'value2', 'new value' 'value3', 'value4', 'value5', 'value6'];

Answer 2

What you have is an object ( {} ), not an array ( [] ). Keys in objects don't have a guaranteed ordering, so you can't insert one at a specific point; they're just properties of that object.

Answer 3

Thanks for the input. I was hoping their was an equivalent to splice for objects that I had missed. Obviously not so I resorted to good old map and rebuild.

function objectInsertafterkey(object, newKey, newVal, insertAfterkey){
newObject={};
$.map(object, function(value, key) {    
if(key == insertAfterkey){
newObject[key] = value;
newObject[newKey] = newVal;
}
else
{
newObject[key] = value;
}
});
return newObject;
}

If their is a better way to insert into objects feel free to let me know.

Answer 4

do like this,use object:

 var myArray = {key1: value1, key2: value2};

add new:

myArray.key3 = "value3";

Answer 5

This may help you:

the arr.splice will add a new value to existing array

http://www.w3schools.com/jsref/jsref_splice.asp

Answer 6

As jAndy says, if you want a specific order, use arrays.

Alternatively, you can sort the keys before use if they have sortable names (like in your example).