Question

Consider this Array

var LIST =[];

LIST['C']=[];
LIST['B']=[];

LIST['C']['cc']=[];
LIST['B']['bb']=[];  

LIST['C']['cc'].push('cc0');
LIST['C']['cc'].push('cc1');
LIST['C']['cc'].push('cc2');
LIST['B']['bb'].push('bb0');
LIST['B']['bb'].push('bb1');
LIST['B']['bb'].push('bb2');

I can loop through this array like

  for(var i in LIST){

      console.log(i)//C,B
      var level1=LIST[i];

      for(var j in level1){
        console.log(j)//cc,bb
        // etc...
      }

   }

Fine.. I have few basic questions.

1.How to sort the array in each level?

One level can be sort by .sort(fn) method . How can i pass to inner levels?

2.Why the indexOf method does not works to find the elements in first two levels?

If it’s because of the a non string parameter .. how can i search an array items in array if the item is not string?

3.How for(var i in LIST) works ?
I just need a basic understanding of indexing and looping through array ..

Thanks ..

Answer 1

LIST is NOT a three dimensional array in Javascript, it is just an array.

//declare an array which names LIST.
var LIST = [];

//set a property named 'C' of the LIST to be an array.
LIST['C']=[];
//set a property named 'B' of the LIST to be an array.
LIST['B']=[];

//set a property named 'cc' of the 'LIST.C'(which is an array object)
LIST['C']['cc']=[];
//set a property named 'bb' of the 'LIST.B'(which is an array object)
LIST['B']['bb']=[];  

The fact is you only need to let the last level to be an array, see my example code below.

function iterateOrderd(obj) {
    if (obj instanceof Array) {
        obj.sort();
        for (var j = 0, l=obj.length; j < l; j++) {
            console.log(obj[j]);
        }
    } else {
        var sortable = [];
        for (var i in obj) {
            if (obj.hasOwnProperty(i)) {
                sortable.push(i);
            }
        }
        sortable.sort();
        for (var j = 0, l=sortable.length; j < l; j++) {
            console.log(sortable[j]);
            iterateOrderd(obj[sortable[j]]);
        }
    }
}


var LIST = {};

LIST['C'] = {};
LIST['B'] = {};

LIST['C']['cc']=[];
LIST['B']['bb']=[];  

LIST['C']['cc'].push('cc0');
LIST['C']['cc'].push('cc1');
LIST['C']['cc'].push('cc2');
LIST['B']['bb'].push('bb0');
LIST['B']['bb'].push('bb1');
LIST['B']['bb'].push('bb2');

iterateOrderd(LIST);