How merge mutil object in array with lodash? - vue.js

Question

I have a bit of problems with my code :
[
{
"key": 0,
"server": 0
},
{
"key": 0,
"server": 1
},
{
"key": 1,
"server": 0
}
]
how i can result to :
[
{ key: 0 , server:[0,1] },
{ key: 1 , server:[0] }
]
I'm using _.groupBy but it does not return results as expected.
How merge mutil object in array with lodash?

Answer 1

One solution would be to use a combination of groupBy, map, and mergeWith.
So first, you group the items by key, so in this example it will return an object with 0 and 1 as the keys which will contain the grouped items.
Then you use .map to iterate through the returned object and get the grouped values.
Finally, you use .mergeWith with a customizer function which you can use to customize the how the values of the server key is merged.
const servers = [{
"key": 0,
"server": 0
},
{
"key": 0,
"server": 1
},
{
"key": 1,
"server": 0
}
];
function customizer(objValue, srcValue, key, fourth) {
if (key === 'server') {
if (!_.isArray(objValue)) objValue = [objValue];
return objValue.concat(srcValue);
}
}
let test = _(servers)
.groupBy('key')
.map((values, key) => {
if (values.length === 1) {
values[0].server = [values[0].server];
return values[0];
}
return _.mergeWith(...values, customizer);
})
.value();
console.log(test);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.11/lodash.min.js"></script>

Answer 2

new Vue({
el: "#app",
data: {
needMergedArray: [
{
key: 0,
server: 0
},
{
key: 0,
server: 1
},
{
key: 1,
server: 0
}
],
},
methods: {
mergeObject() {
let merged = [];
this.needMergedArray.map(item => {
let found = false;
merged.map(element => {
if(item.key === element.key) {
found = true;
if(!element.server) {
//const myserver = [item.server];
element.server =[item.server];
} else {
element.server.push(item.server);
}
}
});
if(!found) {
const myserver = [item.server];
merged.push({key: item.key, server: myserver});
}
found = false;
});
return merged;
}
}
})

Answer 3

// one loop solution: https://jsfiddle.net/haianhnc/2mhsquad/78
mergeObject() {
let merged = {};
this.needMergedArray.map(item => {
merged = {...merged, [item.key]: {key: [item.key], server: (merged[item.key] && merged[item.key].server || []).concat(item.server)}};
});
return Object.values(merged);
}
}

Answer 4

Haven't tested yet
arr.reduce(function(acc,value){
const isExists = acc.findIndex(({key})=>key===value.key)
if(!isExists){
acc.push(value)
} else {
let servers = acc[isExists].server
if(!Array.isArray(servers))
servers = [servers]
servers.push(value.server)
servers = _.uniq(servers)
acc[isExists].server = servers
}
return acc
},[])