add after ary assign assignIn assignInWith assignWith at before bind bindAll bindKey camelCase capitalize castArray ceil chain chunk clamp clone cloneDeep cloneDeepWith cloneWith compact concat conformsTo countBy create curry curryRight debounce deburr defaults defaultsDeep defer delay difference divide drop dropRight each eachRight endsWith entries entriesIn eq escape every extend extendWith fill filter find findIndex findKey findLast findLastIndex findLastKey first flatMap flatMapDeep flatMapDepth flatten flattenDeep flattenDepth flip floor forEach forEachRight forIn forInRight forOwn forOwnRight fromPairs functions functionsIn get groupBy gt gte has hasIn head inRange includes indexOf initial intersection invert invertBy invoke invokeMap isArguments isArray isArrayBuffer isArrayLike isArrayLikeObject isBoolean isBuffer isDate isElement isEmpty isEqual isEqualWith isError isFinite isFunction isInteger isLength isMap isMatch isMatchWith isNaN isNative isNil isNull isNumber isObject isObjectLike isPlainObject isRegExp isSafeInteger isSet isString isSymbol isTypedArray isUndefined isWeakMap isWeakSet join kebabCase keyBy keys keysIn last lastIndexOf lowerCase lowerFirst lt lte map mapKeys mapValues max maxBy mean meanBy memoize merge mergeWith min minBy multiply negate nth omit omitBy once orderBy overArgs pad padEnd padStart parseInt partial partialRight partition pick pickBy pull pullAll pullAllBy pullAllWith pullAt random rearg reduce reduceRight reject remove repeat replace rest result reverse round sample sampleSize set setWith shuffle size slice snakeCase some sortBy sortedIndex sortedIndexOf sortedLastIndex sortedLastIndexOf sortedUniq split spread startCase startsWith subtract sum sumBy tail take takeRight tap template throttle thru toArray toFinite toInteger toLength toLower toNumber toPairs toPairsIn toPlainObject toSafeInteger toString toUpper transform trim trimEnd trimStart truncate unary unescape union uniq uniqBy uniqWith unset unzip unzipWith update updateWith upperCase upperFirst values valuesIn without words wrap wrapperAt wrapperChain wrapperCommit wrapperFlatMap wrapperLodash wrapperNext wrapperPlant wrapperReverse wrapperToIterator wrapperValue xor zip zipObject zipObjectDeep zipWith

Lodash _.keysIn

Overview

The lodash _.keysIn method is a utility function that retrieves all the property names of an object, including inherited properties that are part of the object's prototype chain. The method returns an array of strings containing the property names.

This method is similar to the plain JavaScript Object.keys() method, but with the added functionality of including inherited properties in the result. It traverses up the prototype chain of an object to obtain its complete set of keys.

_.keysIn can be used in situations where the object being worked on is known to have properties that come from a prototype chain. Further, this utility method returns an unordered list of the property names on the object.

To use the lodash _.keysIn method, simply call it with the object as the argument:

_.keysIn(object)

Where 'object' is the source object whose properties are to be enumerated.

For instance, given an object:

const person = { name: 'John', age: 20 }
const student = Object.create(person, { id: { value: 1, enumerable: true } })

Calling the _.keysIn helper with the student object would yield the following item:

_.keysIn(student) // ['id', 'name', 'age']

It is crucial to note that iterating over an object's own properties is generally faster than iterating over all of its properties, including those inherited from its prototype chain. Therefore, unless inheriting properties is essential or necessary to the task at hand, the native and faster Object.keys() method should be preferred to lodash's _.keysIn.