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 _.isNaN

Overview

The lodash _.isNaN method is a utility function that checks if a given value is NaN (Not-A-Number) or not. It returns a boolean value denoting whether the provided value is NaN or not. This method supports both number and string data types.

This method uses the global isNaN() function to determine if the value passed is NaN. Since the native isNaN() function coerces non-number values to a number, the lodash implementation adds a number-check before invoking the isNaN() function, ensuring that the value is indeed a number before returning the result.

The _.isNaN method helps in determining the validity of a numeric value. For instance, it can be used to check if the result of a mathematical operation is valid or not. It can also be used to check the validity of the user input, ensuring that only numeric values are accepted.

The example usage of _.isNaN method is illustrated below:

_.isNaN(NaN);
// => true

_.isNaN('NaN');
// => true

_.isNaN(undefined);
// => false

_.isNaN({});
// => false

_.isNaN(true);
// => false

_.isNaN('3');
// => false

In the above example, the first two arguments are considered as NaN, and the method returns true. The next two values are non-numbers, and the method returns false. The last argument can be converted to a number and is therefore considered a valid number rather than NaN.

In conclusion, _.isNaN is a useful function for checking the validity of numeric values. It checks if a given value is NaN by performing a type check on the input and returns a boolean value denoting whether the provided value is NaN or not.