# map-obj > Map object keys and values into a new object ## Install ```sh npm install map-obj ``` ## Usage ```js const mapObject = require('map-obj'); const newObject = mapObject({foo: 'bar'}, (key, value) => [value, key]); //=> {bar: 'foo'} const newObject = mapObject({FOO: true, bAr: {bAz: true}}, (key, value) => [key.toLowerCase(), value]); //=> {foo: true, bar: {bAz: true}} const newObject = mapObject({FOO: true, bAr: {bAz: true}}, (key, value) => [key.toLowerCase(), value], {deep: true}); //=> {foo: true, bar: {baz: true}} const newObject = mapObject({one: 1, two: 2}, (key, value) => value === 1 ? [key, value] : mapObject.mapObjectSkip); //=> {one: 1} ``` ## API ### mapObject(source, mapper, options?) #### source Type: `object` Source object to copy properties from. #### mapper Type: `(sourceKey, sourceValue, source) => [targetKey, targetValue, mapperOptions?] | mapObject.mapObjectSkip` Mapping function. ##### mapperOptions Type: `object` ###### shouldRecurse Type: `boolean`\ Default: `true` Whether `targetValue` should be recursed. Requires `deep: true`. #### options Type: `object` ##### deep Type: `boolean`\ Default: `false` Recurse nested objects and objects in arrays. ##### target Type: `object`\ Default: `{}` Target object to map properties on to. ### mapObject.mapObjectSkip Return this value from a `mapper` function to exclude the key from the new object. ```js const mapObject = require('map-obj'); const object = {one: 1, two: 2} const mapper = (key, value) => value === 1 ? [key, value] : mapObject.mapObjectSkip const result = mapObject(object, mapper); console.log(result); //=> {one: 1} ``` ## Related - [filter-obj](https://github.com/sindresorhus/filter-obj) - Filter object keys and values into a new object ---
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