JavaScript：在 Object 数组中查找值

Question

I've got an array of objects defined like this:

var editionsObj = new Array();
function editionObject(name,description)
{
    this.name = name;
    this.description = description;
}

I need to search the editionsObj array for the existence of a variable in the name field. If no object in array has a name value equal to what I need, I'm going to insert it into the array. I've seen some examples in jQuery but wasn't able to get any to work.

Thanks in advance!

Answer 1

Was able to solve this with code similar to the following:

var objCheck = null;
objCheck = jQuery.grep(editionsObj, function(n, i) {
     return n.name == currentEdition;
});
if ((objCheck == null) || (objCheck.length == 0))
{
     editionsCount++;
     editionsObj[editionsCount] = new editionObject(currentEdition,currentFamily,'');
}

Basically it performs a grep on the object array checking a certain index (name) for the value. If the value doesn't exist, then I perform the add.

Hope it helps someone else!

Answer 2

I'm going to assume that each element of your array has only two properties. If that's correct, then forget the idea of having named properties and just use a JS object:

var editionsObj = {};
function addIfNotExists(name,description){
  if(!(name in editionsObj)) editionsObj[name] = description;
}

Answer 3

A simple for loop should suffice:

var nameToSearchFor = 'Bob',
    desc = 'whatever',
    alreadyExists = false;
for (var i = 0, il = editionsObj.length; i < il; i++) {
  if (editionsObj[i].name === nameToSearchFor) {
    alreadyExists = true;
    break;
  }
}
if (!alreadyExists) {
  editionsObj.push(new editionObject(nameToSearchFor, desc));
}