JavaScript: Get a copy of the object where the keys have become the values and the values the keys

JavaScript Object: Exercise-16 with Solution

Swap Keys and Values

Write a JavaScript function to get a copy of the object where the keys become the values and the values are the keys.

Sample Solution:

JavaScript Code:

function invert_key_value(obj) {
    var result = {};
    var keys = _keys(obj);
    for (var i = 0, length = keys.length; i < length; i++) {
      result[obj[keys[i]]] = keys[i];
    }
    return result;
  }
function _keys(obj) 
  {
    if (!isObject(obj)) return [];
    if (Object.keys) return Object.keys(obj);
    var keys = [];
    for (var key in obj) if (_.has(obj, key)) keys.push(key);
    return keys;
  }
function isObject(obj) 
 {
    var type = typeof obj;
    return type === 'function' || type === 'object' && !!obj;
  }
console.log(invert_key_value({red: "#FF0000", green: "#00FF00", white: "#FFFFFF"}));

Output:

{"#FF0000":"red","#00FF00":"green","#FFFFFF":"white"}

Flowchart:

Live Demo:

See the Pen javascript-object-exercise-16 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript function that creates a new object by swapping keys and values of the original object.
• Write a JavaScript function that converts an object to key-value pairs, swaps each pair, and rebuilds the object.
• Write a JavaScript function that handles duplicate values by storing them in an array under the new key.
• Write a JavaScript function that validates the input and returns an error if the object contains non-primitive values.

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