iterate over array of objects using map

Question

I want to iterate over an array of objects and pass wach object to a new array.

But the result is always the last object.

obj = [{ text: 'a'},{ text: 'b'}];
obj.map(funktion(item){
    result.push(Ext.merge({xtype: 'button'}, item));
});

// result is twice with text:'b'

It's always the last item. How dies this work?

Ext.merge simply merges two objects, same as JavaScript merge.

EDIT 1: so I changed to

obj = [{ text: 'a'},{ text: 'b'}];
btnsDest = obj.map(function(item){
     return Ext.merge({xtype: 'button'}, item);
});

Still the same. btnsDest[i].text is always 'b'

EDIT 2: so I actually had the following and tagt did not work

button = { xtype: 'button'};
obj = [{ text: 'a'},{ text: 'b'}];
btnsDest = obj.map(function(item){
     return Ext.merge(button, item);
});

So adding the var button to the callback did the trick.

Manoj Awasthi · Accepted Answer · 2015-02-17 05:10:17Z

1

Within the map's callback function you need to return the transformed value (mapped):

obj = [{ text: 'a'},{ text: 'b'}];
obj.map(function(item){
    return Ext.merge({xtype: 'button'}, item);
});

Following is what I tried at my end with node and it works:

function merge_options(obj1,obj2){
    var obj3 = {};
    for (var attrname in obj1) { obj3[attrname] = obj1[attrname]; }
    for (var attrname in obj2) { obj3[attrname] = obj2[attrname]; }
    return obj3;
}

button = { xtype: 'button'};
obj = [{ text: 'a'},{ text: 'b'}];
btnsDest = obj.map(function(item){
         return merge_options(button, item);
});

console.log(JSON.stringify(btnsDest));

Output is:

[{"xtype":"button","text":"a"},{"xtype":"button","text":"b"}]

edited Feb 17, 2015 at 5:10

answered Feb 16, 2015 at 19:11

Manoj Awasthi

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2 Comments

Dinkheller Over a year ago

Aarrrrg. I defined button as an object outside the callback and used button inside the callback merge. That does not work.

Manoj Awasthi Over a year ago

did that work? I am posting something which I tried with node at my end and it works.

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