Array_.chunk_.compact_.concat_.difference_.differenceBy_.differenceWith_.drop_.dropRight_.dropRightWhile_.dropWhile_.fill_.findIndex_.findLastIndex_.flatten_.flattenDeep_.flattenDepth_.fromPairs_.head_.indexOf_.initial_.intersection_.intersectionBy_.intersectionWith_.join_.last_.lastIndexOf_.nth_.pull_.pullAll_.pullAllBy_.pullAllWithCollectionDateFunctionLang_.castArray_.clone_.cloneDeep_.cloneDeepWith_.cloneWith_.conformsTo_.eq_.gt_.gte_.isArguments_.isArray_.isArrayBuffer_.isArrayLike_.isArrayLikeObject_.isBoolean_.isBuffer_.isDate_.isElement_.isEmpty_.isEqual_.isEqualWith_.isError_.isFinite_.isFunction_.isInteger_.isLength_.isMap_.isMatch_.isMatchWith_.isNaN_.isNative_.isNil_.isNull_.isNumberMathObjectSeqString_.camelCase_.capitalize_.deburr_.endsWith_.escape_.escapeRegExp_.kebabCase_.lowerCase_.lowerFirst_.pad_.padEnd_.padStart(string ='',length = 0,chars ='')_.parseInt_.repeat(string ='',n = 1)_.replace(string ='',pattern,replacement)_.snakeCase_.split_.startCase_.startsWith_.template_.toLower_.toUpper_.trim_.trimEnd(string ='',chars = whitespace)_.trimStart_.truncate_.unescape_.upperCase_.upperFirstUtil_.attempt_.bindAll_.cond_.conforms_.constant_.defaultTo_.flow_.flowRight_.identity_.iteratee_.matches_.matchesProperty_.method_.methodOf_.mixin_.noConflict_.noop_.nthArg_.over_.overEvery_.overSome_.property_.propertyOf_.range_.rangeRight_.runInContext_.stubArray()_.stubFalse_.stubObject_.stubString_.stubTrue_.times_.toPath_.uniqueIdMethods检查value以确定是否应该在其位置返回默认值。将defaultValue     返回如果value是NaN,null或undefined。
4.14.0
value (*):要检查的值。     defaultValue (*):默认值。     (*):返回已解析的值。
_.defaultTo(1, 10); // => 1 _.defaultTo(undefined, 10); // => 10