So here is the deal. I have an array that contains a bunch of objects that look something like this:
[{
"this": 5,
"that": 300,
"those": 15
},
{
"this": 6,
"that": 301,
"those": 16
},
{
"this": 7,
"that: 302,
"those": 17
}]
What I want, is an object, that looks like this:
{
"this": [5, 6, 7],
"that": [300, 301, 302],
"those": [15, 16, 17]
}
I don't really know what to call this and by what I searched for, I couldn't find anything similar that would help me.
Try this:
var a = [{
"this": 5,
"that": 300,
"those": 15
},{
"this": 6,
"that": 301,
"those": 16
},{
"this": 7,
"that": 302,
"those": 17
}];
a = a.reduce(
function(obj, item){ // Map the item to the object.
obj.this.push(item.this);
obj.that.push(item.that);
obj.those.push(item.those);
return obj;
},
{"this":[],"that":[],"those":[]} // Default (empty) object.
);
This uses Array.prototype.reduce().
a the reference to the new array. Could assign it to a new variable ofc.For older browsers (i.e. IE8), reduce is not available. If you still want to support these, you can try:
var arr = [{
"this": 5,
"that": 300,
"those": 15
}, {
"this": 6,
"that": 301,
"those": 16
}, {
"this": 7,
"that": 302,
"those": 17
}];
var result = {};
for (var i = 0; i < arr.length; i++) {
for (var x in arr[i]) {
if (!result[x]) {
result[x] = [];
}
result[x].push(arr[i][x]);
}
}
console.log(result);
EDIT: This will also allow modification of the source array without changing the converting code.
[{"this": 5, "that": 300, "those": 15}, {"this": 6, "that": 301, "those": 16 }, {"this": 7, "that": 302, "those": 17}]
.reduce(function(prev, curr) {
return {
"this": [].concat(prev["this"], [curr["this"]]),
"that": [].concat(prev["that"], [curr["that"]]),
"those": [].concat(prev["those"], [curr["those"]]),
};
})
Result:
{"this":[5,6,7],"that":[300,301,302],"those":[15,16,17]}
Test in in console yourself.
By using concat we don't have to pass empty {"this":[],"that":[],"those":[]} initial value.
[{"this": 5, "that": 300, "those": 15}, {"this": 6, "that": 301, "those": 16 }, {"this": 7, "that": 302, "those": 17}]
.reduce(function(prev, curr) {
for (var key in prev) {
prev[key] = [].concat(prev[key], curr[key])
}
return prev;
})
As you can see this version doesn't make any assumptions about key names.
