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 _.has

Overview

The lodash _.has method is a utility function that checks if an object has a given property. It returns a boolean value indicating whether the object has the property or not. The method takes two arguments: the object to check and the property path to query.

The property path may be specified as either a string or an array of strings, with each element representing a key in the object. The _.has method traverses the object hierarchy to locate the property specified in the property path, and returns true if the property is found, false otherwise.

The _.has method can be used in a wide range of scenarios in JavaScript programming. For example, it can be used to test if an object has a certain property before attempting to read or write its value. This can help prevent errors and improve the robustness of the code.

In addition to its primary function of checking for property existence, the _.has method can also be used in functional programming techniques to compose more complex functions. For instance, it can be combined with other lodash methods like _.map and _.filter to create advanced data transformations and filters.

Some examples of using the _.has method are:

const obj = { a: { b: 2 } };

_.has(obj, 'a'); // true
_.has(obj, 'a.b'); // true
_.has(obj, ['a', 'b']); // true

const arr = [{ a: 1 }, { b: 2 }];

_.filter(arr, _.partial(_.has, _, 'a')); //[{ a: 1 }]
_.map(arr, _.partial(_.get, _, 'b', 'unknown')); //[undefined, 2]

In summary, the _.has method is a powerful utility function for checking object property existence and can be used in various scenarios in JavaScript development.