Question

I am wondering if i can get the object property using array. I am getting ‘undefine’ value for this.label[i].xOffset. Any suggestions?

function label() {
    var lbl = this;
    lbl.rText;
    lbl.precision =1;
    lbl.prefix = '';
    lbl.suffix = '';
    lbl.xOffset = this.width/2;
    lbl.yOffset = this.height*82/100    
}
this.NoOfneedles=2;
if (this.NoOfneedles > 1) {
    this.label = [];
    for (i=0;i<this.NoOfneedles;i++) {
        this.label[i]=new label();
        alert("label xOffset:"+this.label[i]+this.label[i].xOffset);
    }
}

Answer 1

Your label object has no width and height properties and already others said you that but if you just define width and height inside your constructor then it could be written as follows

function Label() {
   var lbl = this;
   lbl.width=window.outerWidth;
   lbl.height=window.outerHeight;
   lbl.precision =1;
   lbl.prefix = '';
   lbl.suffix = '';
   lbl.xOffset = lbl.width/2;
   lbl.yOffset = lbl.height*82/100    
}

this.NoOfneedles=2;
if (this.NoOfneedles > 1){
    this.label = [];
    for (i=0;i<this.NoOfneedles;i++){
        this.label[i]=new Label();
        alert ("label xOffset:"+this.label[i].xOffset);
    }
}

Remember this refers to current object and you are using this.width/2; inside your constructor so this=Label and I’ve changed the label to Label and outside the constructor/in global scope this refers to default global object window and in the global scope this.someVar and someVar is same because window is the default global object and by default we don’t need to use it so we can use document.getElementbyId instrad of window.document.getElementbyId.