How to properly pass two objects through two functions in jQuery

Question

My series of methods are like so :

onUpdateAcrossDown ( findAcrossAndDownWords( across_index, down_index ) )

I want to reuse findAcrossAndDownWords, so I'd like it to return my two objects that I can pass into other methods if need be.

findAcrossAndDownWords: function(across_index, down_index) {
  across_word = across_index[0] // <-- not real, just representing that it becomes an object here.
  down_word = down_index[0]
  return [across_word, down_word] // <-- This is where my problem is. Not sure how to return a double param for my parent function.
}

The trouble is, the return I am using does not properly pass across_word, down_word .

onUpdateAcrossDown: function(across_word, down_word) {
 // How do I get across_word and down_word here properly?

Ram · Accepted Answer · 2012-11-05 20:24:21Z

4

If you want to use the values in an array as parameters to a function, you have to call the function with .apply()

var results = findAcrossAndDownWords( across_index, down_index );
onUpdateAcrossDown.apply(whatever, results);

The .apply() method takes two arguments: the value to use for this in the called function, and an array containing the parameters to pass.

edited Nov 5, 2012 at 20:24

Ram

145k16 gold badges174 silver badges201 bronze badges

answered Nov 5, 2012 at 20:22

Pointy

415k62 gold badges600 silver badges632 bronze badges

Sign up to request clarification or add additional context in comments.

7 Comments

Trip Over a year ago

strikes again! Thanks so much!

Trip Over a year ago

Is that whatever relevant? It's returning undefined ;)

Pointy Over a year ago

@Trip well I couldn't tell from your code whether the this value inside the function is important. If it is, then that's what you pass; otherwise it doesn't really matter. (By "whatever" I just meant, "something appropriate", in other words.)

Elias Van Ootegem Over a year ago

@Trip: I do hope you know what this references when you're passing it to .apply, because this can point to the global object, so you might be creating unwanted globals or trying to access undefined properties

Pointy Over a year ago

@EliasVanOotegem well if he's passing undefined then it's probably OK, so long as it's working.

|

Elias Van Ootegem · Accepted Answer · 2012-11-05 20:25:02Z

You could, instead of nesting calls, pass the second function as an argument:

findAcrossAndDownWords(across_index, down_index, onUpdateAcrossDown);

function findAcrossAndDownWords(object1, object2, callNext)
{
    //do stuff
    return callNext(object1, object2);
}

Or, change the function definition of the second function to:

function UpdateAcrossDown(anArray)
{
    var obj1 = anArray[0], obj2 = anArray[1];
}

Or, if you're allways going to call the same function:

function findAcrossAndDownWords(object1, object2, callNext)
{
    //do stuff
    return UpdateAcrossDown(object1, object2);//loses call context
    return UpdateAcrossDown.apply(this,arguments);//preserve called context
    //or even
    return UpdateAcrossDown.apply(this,[object1,object2]);//preserve called context
}

Collectives™ on Stack Overflow

How to properly pass two objects through two functions in jQuery

2 Answers 2

7 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

7 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related