Deep replace a value within an object or array (using lodash or underscore)

replacePropertyValue.js

/**
 * Deep search and replaces the given property value "prevVal" with "newVal"
 * @param  {any} prevVal [description]
 * @param  {any} newVal  [description]
 * @param  {object|array} object the original object or array in which the values should be replaced
 * @return {object|array}        the new object or array
 */
function replacePropertyValue(prevVal, newVal, object) {
  const newObject = _.clone(object);

  _.each(object, (val, key) => {
    if (val === prevVal) {
      newObject[key] = newVal;
    } else if (typeof(val) === 'object' || typeof(val) === 'array') {
      newObject[key] = replacePropertyValue(prevVal, newVal, val);
    }
  });

  return newObject;
}

typeof(val) === 'array'

typeof [] always === object, so this OR check is redundant.

FYI: You can do it with lodash like this: _.cloneDeepWith(object, value => value === prevVal ? newVal : undefined).

You could also use the reviver function using JSON.parse. It's quite efficient too. i.e.:

JSON.parse(JSON.stringify(object), (key, value) => {
if (key=='propToChange') {
return newValue;
} else {
return value;
}
})

@cdelgadob thanks for that!

FYI: You can do it with lodash like this: _.cloneDeepWith(object, value => value === prevVal ? newVal : undefined).

@ypresto as I would do, if instead of passing fn(prevVal, newVal, object), I would always have to pass inside an array with 1 object or more, example fn([{prevVal: 'old value', newVal: 'new value' }], object)

I liked your solution because it is cleaner.

Great solution @cdelgadob!

You could also use the reviver function using JSON.parse. It's quite efficient too. i.e.:

Note that JSON.parse(JSON.stringify(object))) has some side effects, such as converting dates into strings (see here).