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lodash: mapping array to object

Another way with lodash 4.17.2

_.chain(params)
    .keyBy('name')
    .mapValues('input')
    .value();

or

_.mapValues(_.keyBy(params, 'name'), 'input')

or with _.reduce

_.reduce(
    params,
    (acc, { name, input }) => ({ ...acc, [name]: input }),
    {}
)

You should be using _.keyBy to easily convert an array to an object.

Docs here

Example usage below:

var params = [
    { name: 'foo', input: 'bar' },
    { name: 'baz', input: 'zle' }
];
console.log(_.keyBy(params, 'name'));
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

If required, you can manipulate the array before using _.keyBy or the object after using _.keyBy to get the exact desired result.


Yep it is here, using _.reduce

var params = [
    { name: 'foo', input: 'bar' },
    { name: 'baz', input: 'zle' }
];

_.reduce(params , function(obj,param) {
 obj[param.name] = param.input
 return obj;
}, {});

This seems like a job for Object.assign:

const output = Object.assign({}, ...params.map(p => ({[p.name]: p.input})));

Edited to wrap as a function similar to OP's, this would be:

const toHash = (array, keyName, valueName) => 
    Object.assign({}, ...array.map(o => ({[o[keyName]]: o[valueName]})));

(Thanks to Ben Steward, good thinking...)


You can use one liner javascript with array reduce method and ES6 destructuring to convert array of key value pairs to object.

arr.reduce((map, { name, input }) => ({ ...map, [name]: input }), {});

This is probably more verbose than you want, but you're asking for a slightly complex operation so actual code might be involved (the horror).

My recommendation, with zipObject that's pretty logical:

_.zipObject(_.map(params, 'name'), _.map(params, 'input'));

Another option, more hacky, using fromPairs:

_.fromPairs(_.map(params, function(val) { return [val['name'], val['input']));

The anonymous function shows the hackiness -- I don't believe JS guarantees order of elements in object iteration, so callling .values() won't do.


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