Camel Case Keys

mediumcodingJavaScriptObjectsStrings~25 min

Asked at Google, Meta, Amazon

Overview

Implement camelCaseKeys(object) that deeply converts all keys from snake_case to camelCase.

Examples

camelCaseKeys({ user_name: 'John', user_info: { first_name: 'John' }});
// { userName: 'John', userInfo: { firstName: 'John' }}

Solution

Reveal solution

function camelCaseKeys(value) {
  if (value === null || typeof value !== 'object') return value;
  if (Array.isArray(value)) return value.map(item => camelCaseKeys(item));
  const result = {};
  for (const [k, v] of Object.entries(value)) {
    const camel = k.replace(/_([a-z])/g, (_, c) => c.toUpperCase());
    result[camel] = camelCaseKeys(v);
  }
  return result;
}

camel-case-keys.js

Camel Case Keys

mediumcodingJavaScriptObjects

Overview

Implement camelCaseKeys(object) that deeply converts all keys from snake_case to camelCase.

Examples

camelCaseKeys({ user_name: 'John', user_info: { first_name: 'John' }});
// { userName: 'John', userInfo: { firstName: 'John' }}

Solution

Reveal solution

function camelCaseKeys(value) {
  if (value === null || typeof value !== 'object') return value;
  if (Array.isArray(value)) return value.map(item => camelCaseKeys(item));
  const result = {};
  for (const [k, v] of Object.entries(value)) {
    const camel = k.replace(/_([a-z])/g, (_, c) => c.toUpperCase());
    result[camel] = camelCaseKeys(v);
  }
  return result;
}

NameTopicDifficulty

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