jonschlinkert/get-value

$ npm install --save get-value

import getValue from 'get-value';
// or
import { getValue } from 'get-value';
// or
const getValue = require('get-value');
const obj = { a: { b: { c: { d: 'foo' } } } };

console.log(getValue(obj));            //=> { a: { b: { c: { d: 'foo' } } } };
console.log(getValue(obj, 'a'));       //=> { b: { c: { d: 'foo' } } }
console.log(getValue(obj, 'a.b'));     //=> { c: { d: 'foo' } }
console.log(getValue(obj, 'a.b.c'));   //=> { d: 'foo' }
console.log(getValue(obj, 'a.b.c.d')); //=> 'foo'

console.log(getValue({ 'a.b': { c: 'd' } }, 'a.b.c'));
//=> 'd'

console.log(getValue({ 'a.b': { c: { 'd.e': 'f' } } }, 'a.b.c.d.e'));
//=> 'f'

console.log(getValue({ a: { b: { c: { d: 'foo' } } }, e: [{ f: 'g' }, { f: 'h' }] }, 'e.1.f'));
//=> 'h'

console.log(getValue({ a: { b: [{ c: 'd' }] } }, 'a.b.0.c'));
//=> 'd'

console.log(getValue({ a: { b: [{ c: 'd' }, { e: 'f' }] } }, 'a.b.1.e'));
//=> 'f'

function foo() {}
foo.bar = { baz: 'qux' };

console.log(getValue(foo));
//=> { [Function: foo] bar: { baz: 'qux' } }

console.log(getValue(foo, 'bar'));
//=> { baz: 'qux' }

console.log(getValue(foo, 'bar.baz'));
//=> qux

console.log(getValue({ a: { b: 'c' } }, ['a', 'b']));
//=> 'c'

const obj = { foo: { a: { b: { c: { d: 'e' } } } } };
console.log(getValue(obj, 'foo.a.b.c.d', { default: true }));  //=> 'e'
console.log(getValue(obj, 'foo.bar.baz', { default: true }));  //=> true
console.log(getValue(obj, 'foo.bar.baz', { default: false })); //=> false
console.log(getValue(obj, 'foo.bar.baz', { default: null }));  //=> null

// you can also pass the default value as the last argument
// (this is necessary if the default value is an object)
console.log(getValue(obj, 'foo.a.b.c.d', true));  //=> 'e'
console.log(getValue(obj, 'foo.bar.baz', true));  //=> true
console.log(getValue(obj, 'foo.bar.baz', false)); //=> false
console.log(getValue(obj, 'foo.bar.baz', null));  //=> null

const isEnumerable = Object.prototype.propertyIsEnumerable;
const options = {
  isValid: (key, obj) => isEnumerable.call(obj, key)
};

const obj = {};
Object.defineProperty(obj, 'foo', { value: 'bar', enumerable: false });

console.log(getValue(obj, 'foo', options));           //=> undefined
console.log(getValue({}, 'hasOwnProperty', options)); //=> undefined
console.log(getValue({}, 'constructor', options));    //=> undefined

// without "isValid" check
console.log(getValue(obj, 'foo', options));           //=> bar
console.log(getValue({}, 'hasOwnProperty', options)); //=> [Function: hasOwnProperty]
console.log(getValue({}, 'constructor', options));    //=> [Function: Object]

const obj = { 'a.b': { c: { d: 'e' } } };

// example of using a string to split the object path
const options = { split: path => path.split('/') };
console.log(getValue(obj, 'a.b/c/d', options)); //=> 'e'

// example of using a regex to split the object path
// (removing escaped dots is unnecessary, this is just an example)
const options = { split: path => path.split(/\\?\./) };
console.log(getValue(obj, 'a\\.b.c.d', options)); //=> 'e'

const obj = { 'a.b': { c: { d: 'e' } } };

console.log(getValue(obj, 'a.b/c/d', { separator: '/' }));
//=> 'e'

console.log(getValue(obj, 'a\\.b.c.d', { separator: /\\?\./ }));
//=> 'e'

const obj = { 'a/b': { c: { d: 'e' } } };
const options = {
  // when segs === ['a', 'b'] use a "/" to join, otherwise use a "."
  join: segs => segs.join(segs[0] === 'a' ? '/' : '.')
};

console.log(getValue(obj, 'a.b.c.d', options));
//=> 'e'

const target = { 'a-b': { c: { d: 'e' } } };
const options = { joinChar: '-' };
console.log(getValue(target, 'a.b.c.d', options));
//=> 'e'

# deep (338 bytes)
  dot-prop x 5,319,159 ops/sec ±0.76% (93 runs sampled)
  dotty x 3,870,706 ops/sec ±0.26% (96 runs sampled)
  get-value x 8,788,576 ops/sec ±0.19% (100 runs sampled)
  getobject x 1,979,207 ops/sec ±0.17% (98 runs sampled)
  object-path x 1,761,814 ops/sec ±0.25% (100 runs sampled)

  fastest is get-value (by 65% avg)

# root (215 bytes)
  dot-prop x 41,761,355 ops/sec ±0.89% (93 runs sampled)
  dotty x 29,943,256 ops/sec ±0.55% (99 runs sampled)
  get-value x 65,184,370 ops/sec ±1.00% (96 runs sampled)
  getobject x 13,780,598 ops/sec ±0.35% (98 runs sampled)
  object-path x 21,255,148 ops/sec ±0.45% (101 runs sampled)

  fastest is get-value (by 56% avg)

# shallow (91 bytes)
  dot-prop x 21,019,241 ops/sec ±0.46% (93 runs sampled)
  dotty x 15,912,833 ops/sec ±0.76% (96 runs sampled)
  get-value x 19,824,809 ops/sec ±0.40% (91 runs sampled)
  getobject x 7,537,059 ops/sec ±0.15% (97 runs sampled)
  object-path x 8,519,654 ops/sec ±0.21% (99 runs sampled)

  fastest is dot-prop (by 6% avg)

$ git clone https://github.com/jonschlinkert/get-value.git

$ npm install && node benchmark