Is there any method to merge 2 arrays of objects like this
var a = [{id: 1, val: 1},{id: 2, val: 2},{id: 3, val: 3},{id: 4, val: 4},{id: 5, val: 5}];
var b = [{id: 21, val: 21},{id: 22, val: 22},{id: 23, val: 23}]
//final result should be
c = [
{id:1, val: 1},
{id:21, val: 21},
{id:2, val: 2},
{id:22, val: 22},
{id:3, val: 3},
{id:23, val: 23},
{id:4, val: 4},
{id:5, val: 5}
]
offcourse I can create it by myself, but just want to check whether lodash provide it or not
You could first zip the arrays, flatten the result and then use compact to remove the missing array elements (zip adds them as undefined):
var c = _.compact(_.flatten(_.zip(a,b)))
Or using chaining:
var c = _(a)
.zip(b)
.flatten()
.compact()
.value()
var a = [{id: 1, val: 1},{id: 2, val: 2},{id: 3, val: 3},{id: 4, val: 4},{id: 5, val: 5}];
var b = [{id: 21, val: 21},{id: 22, val: 22},{id: 23, val: 23}]
var c = _(a)
.zip(b)
.flatten()
.compact()
.value()
document.getElementById('results').textContent = JSON.stringify(c);<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>
<pre id="results"></pre>
var a = [{id: 1, val: 1},{id: 2, val: 2},{id: 3, val: 3},{id: 4, val: 4},{id: 5, val: 5}];
var b = [{id: 21, val: 21},{id: 22, val: 22},{id: 23, val: 23}];
// loop through the biggest array and reduce the result (no need for the value we just need the accumulator and the index)
var result = _.reduce(a.length < b.length? b: a, function(res, _, i) {
if(i < a.length) res.push(a[i]); // if there is still elements in a, push the current one
if(i < b.length) res.push(b[i]); // if there is still elements in b, push the current one
return res;
}, []);
console.log(result);<script src="https://cdn.jsdelivr.net/lodash/4.17.4/lodash.min.js"></script>
length determining out of loop. Hint: See my approach aLen = a.length, bLen = b.length
_.forEach and push to an outer variable result and do all the tests outside!In plain Javascript, you could use a function which iterates to the minimum length of both, assembles the values and concat the rest at the end.
function insert(a, b) {
var c = [],
i = 0,
l = Math.min(a.length, b.length);
while (i < l) {
c.push(a[i], b[i]);
i++;
}
return c.concat(a.slice(i), b.slice(i));
}
var a = [{ id: 1, val: 1 }, { id: 2, val: 2 }, { id: 3, val: 3 }, { id: 4, val: 4 }, { id: 5, val: 5 }],
b = [{ id: 21, val: 21 }, { id: 22, val: 22 }, { id: 23, val: 23 }];
console.log(insert(a, b));.as-console-wrapper { max-height: 100% !important; top: 0; }Ecmascript5 solution using Math.max()(to find the larger array size) and Array.prototype.push() functions:
var a = [{id: 1, val: 1},{id: 2, val: 2},{id: 3, val: 3},{id: 4, val: 4},{id: 5, val: 5}],
b = [{id: 21, val: 21},{id: 22, val: 22},{id: 23, val: 23}],
maxLen = Math.max(a.length, b.length), aLen = a.length, bLen = b.length,
maxList = aLen > bLen ? a : b;
result = [];
for (var i = 0; i < maxLen; i++) {
(i < aLen && i < bLen) ? result.push(a[i], b[i]) : result.push(maxList[i]);
}
console.log(result);