如何使用Javascript将迭代器索引号附加到数组中的每个项目？

Question

How do you append a key called 'Index' with a value being the dictionaries index to the below array? The array should be sorted by Timestamp before this occurs so that TimeStamp:111 comes first and TimeStamp:222 comes second, etc.

For example, see below for original array

items = [
            {Id: "01", Name: "A", Price: "1.00", Quantity: "1",TimeStamp:111},
            {Id: "02", Name: "B", Price: "10.00", Quantity: "1",TimeStamp:222},
            {Id: "04", Name: "C", Price: "9.50", Quantity: "10",TimeStamp:434},
            {Id: "03", Name: "a", Price: "9.00", Quantity: "2",TimeStamp:545},
            {Id: "06", Name: "b", Price: "100.00", Quantity: "2",TimeStamp:676},
            {Id: "05",Name: "c", Price: "1.20", Quantity: "2",TimeStamp:777}
        ];

The resulting array should look like this:

items = [
    {Id: "01", Name: "A", Price: "1.00", Quantity: "1",TimeStamp:111,Index:1},
            {Id: "02", Name: "B", Price: "10.00", Quantity: "1",TimeStamp:222,Index:2},
            {Id: "04", Name: "C", Price: "9.50", Quantity: "10",TimeStamp:434,Index:3},
            {Id: "03", Name: "a", Price: "9.00", Quantity: "2",TimeStamp:545,Index:4},
            {Id: "06", Name: "b", Price: "100.00", Quantity: "2",TimeStamp:676,Index:5},
            {Id: "05",Name: "c", Price: "1.20", Quantity: "2",TimeStamp:777,Index:6}
        ];

Here's my attempt: http://jsfiddle.net/chrisguzman/f7dnfrjf/ I've figured out how to append an item to each dictionary, but not how to append its respective iterator.

Also, here it is in angular js (bonus points if there is a way to do it with angular): http://codepen.io/chriscruz/pen/GgjGvO?editors=101

Answer 1

Index started from 0, so you need add +1 for each index, like this

items.forEach(function (d, index) {
    d.Index = index + 1;
});

Demo: http://jsfiddle.net/f7dnfrjf/1/

Angular demos:

1. http://codepen.io/pen/ZYpRag - indexes are displayed as 2, 3, 5, 6

2. http://codepen.io/pen/zxKapG - indexes are displayed as 1, 2, 3, 4

Answer 2

The runtime system passes 3 parameters to .forEach() : the first is the array element, the second is the index, and the third is the array itself.

Thus:

items.forEach(function (d, i) {
    d.Index = i;
});