formatting json data to be camelCased

Question

I get a json response from the server that looks something like this:

{
    \"Response\": {
        \"FirstName\": \"John\",
        \"LastName\": \"Smith\",
            


        

Answer 1

Here is a functional recursive (ES6) approach.

function convertKeysToCamelCase(o) {
  if (o === null || o === undefined) {
    return o;
  } else if (Array.isArray(o)) {
    return o.map(convertKeysToCamelCase);
  }
  return typeof o !== 'object' ? o : Object.keys(o).reduce((prev, current) => {
    const newKey = `${current[0].toLowerCase()}${current.slice(1)}`;
    if (typeof o[current] === 'object') {
      prev[newKey] = convertKeysToCamelCase(o[current]);
    } else {
      prev[newKey] = o[current];
    }
    return prev;
  }, {});
}

// successfully tested input
const o = {
  SomeNum: 1,
  SomeStr: 'a',
  SomeNull: null,
  SomeUndefined: undefined,
  SomeBoolean: true,
  SomeNaN: NaN,
  NestedObject: {
    SomeSentence: 'A is for apple',
    AnotherNested: {
      B: 'is for blahblah'
    }
  },
  NumArray: [1, 2, 3, 4],
  StringArray: ['a', 'b', 'c'],
  BooleanArray: [true, false],
  ArrayOfArrays: [[1,2,], ['a','b']],
  ObjectArray: [{Foo:'bar'}, {Hello:'world', Nested:{In:'deep'}}],
  MixedArray: [1,'a', true, null, undefined, NaN, [{Foo:'bar'}, 'wat']]
}

const output = convertKeysToCamelCase(o);

console.log(output.mixedArray[6][0].foo); // 'bar'