Smart way to add elements to all objects in array? js/jquery/knockout

Question

for example I have an array like this:

var t = ko.observableArray([
  {"FoodName":"Rice","FoodOften":"2"},
  {"FoodName":"Apple","FoodOften":"3"}
]);

How can I add an static item to all of them like below in a smart way?

[
  {"Student":"1","FoodName":"Rice","FoodOften":"2"},    
  {"Student":"1","FoodName":"Apple","FoodOften":"3"}      
]

I know I can loop t().length to add t()[n].Student="1" but just wondering is there any smart way for knockout?

S McCrohan · Accepted Answer · 2015-05-12 02:45:36Z

1

Every variation on answering this question is going to be some form of 'iterate over the array and add the value to each object'. A few:

t.forEach(function(entry) {
    entry.Student = 1;
});

var newT = t.map(function(entry) {
    entry.Student = 1;
    return entry;
});

for (var i = 0; i++; i< t.length) {
    t[i].Student = 1;
}

Incidentally, at least in Chrome, jsperf says the first is the most efficient of those three.

edited May 12, 2015 at 2:45

answered May 12, 2015 at 2:36

S McCrohan

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