Question

I am looking to create a set of dynamically created arrays stored inside an object. the outcome would be something similar to this…

object.array0.length = 5, object.array1.length = 4, etc

the name of the array would be generated from within a for loop based on a numerical value declared elsewhere in the application.

Here is the code that I have…

var obj = {};
var weekNum = 4;

for(i=0; i < weekNum.length;i++) {
    obj['week'+i] = [];
    obj['week'+i].push(day);

    console.log('days stored in week0: '+obj.week0.length);
}

What seems to be happening is that obj['week'+i] doesn’t realize that it is an array, and the push command doesn’t seem to be enough to make it think so. So as a resulting value of obj.week0.length is always 1 with the actual value just being replaced each time as opposed to the array being incremented.

Also fyi,
The parameter day in the above code would be passed in from another function representing any chosen day (Mon, Tues, etc)… However, the sequence and the amount of days passed in could differ but will never exceed 5 (m-f).

Answer 1

Looks like a logic problem to me. You’re always only inserting 1 day into the array unless day represents something else altogether.

var obj = {};
var weekNum = 4;

// var was missing :)
for(var i = 0; i < weekNum.length; i++) {
    // check if entry exists before creating new.
    obj['week'+i] = obj['week'+i] || [];
    // you're always only inserting 1 value inside the week array
    // don't you want to loop through the number of days
    // and insert a day entry for *this* week for each day. like this?
    // days is another array of, hmm.. days
    for(var j = 0; j <days.length; j++) {
        obj['week'+i].push(days[j]);
    }

    console.log('days stored in week0: '+obj.week0.length);
}