lodash-contrib

### function.predicates > Functions which return whether the input meets a condition. -------------------------------------------------------------------------------- #### isAssociative **Signature:** `isAssociative(value:Any)` Returns a boolean indicating whether or not the value is an associative object. An associative object is one where its elements can be accessed via a key or index (e.g. arrays, `arguments`, objects). ```javascript _.isAssociative(["Athens", "Sparta"]); // => true _.isAssociative(42); // => false ``` -------------------------------------------------------------------------------- #### isDecreasing **Signature:** `_.isDecreasing(values:Any...)` Checks whether the arguments are monotonically decreasing values (i.e. whether each argument is less than the previous argument.) ```javascript _.isDecreasing(3, 2, 1); // => true _.isDecreasing(15, 12, 2); // => true _.isDecreasing(2, 3); // => false ``` -------------------------------------------------------------------------------- #### isEven **Signature:** `_.isEven(value:Any)` Checks whether the value is an even number. ```javascript _.isEven(12); // => true _.isEven(3); // => false _.isEven({}); // => false ``` -------------------------------------------------------------------------------- #### isFloat **Signature:** `_.isFloat(value:Any)` Checks whether the value is a "float." For the purposes of this function, a float is a numeric value that is not an integer. A numeric value may be a number, a string containing a number, a `Number` object, etc. **NOTE:** JavaScript itself makes no distinction between integers and floats. For the purposes of this function both `1` and `1.0` are considered integers. ```javascript _.isFloat(1.1); // => true _.isFloat(1); // => false _.isFloat(1.0); // => false _.isFloat("2.15"); // => true ``` -------------------------------------------------------------------------------- #### isIncreasing **Signature:** `_.isIncreasing(value:Any...)` Checks whether the arguments are monotonically increasing values (i.e. each argument is greater than the previous argument.) ```javascript _.isIncreasing(1, 12, 15); // => true _.isIncreasing(1); // => true _.isIncreasing(5, 4); // => false ``` -------------------------------------------------------------------------------- #### isIndexed **Signature:** `_.isIndexed(value:Any)` Checks whether the value is "indexed." An indexed value is one which accepts a numerical index to access its elements. (e.g. arrays and strings) **NOTE:** lodash does not support cross-browser consistent use of strings as array-like values, so be wary in IE 8 when using string objects and in IE7 and earlier when using string literals & objects. ```javascript _.isIndexed("Socrates"); // => true _.isIndexed({poison: "hemlock"}); // => false ``` -------------------------------------------------------------------------------- #### isInstanceOf **Signature:** `_.isInstanceOf(value:Any, constructor:Function)` Checks whether the value is an instance of the constructor. ```javascript _.isInstanceOf(new Date(), Date); // => true _.isInstanceOf("Hippocrates", RegExp); // => false ``` -------------------------------------------------------------------------------- #### isInteger **Signature:** `_.isInteger(value:Any)` Checks whether the value is a numeric integer. A numeric value can be a string containing a number, a `Number` object, etc. ```javascript _.isInteger(18); // => true _.isInteger("18"); // => true _.isInteger(2.5); // => false _.isInteger(-1); // => true ``` -------------------------------------------------------------------------------- #### isJSON **Signature:** `_.isJSON(value:Any)` Checks whether the value is valid JSON. [See the spec](http://www.json.org/) for more information on what constitutes valid JSON. **NOTE:** This function relies on `JSON.parse` which is not available in IE7 and earlier. ```javascript _.isJSON('{ "name": "Crockford" }'); // => true _.isJSON({ name: "Crocket" }); // => false ``` -------------------------------------------------------------------------------- #### isNegative **Signature:** `_.isNegative(value:Any)` Checks whether the value is a negative number. ```javascript _.isNegative(-2); // => true _.isNegative(5); // => false ``` -------------------------------------------------------------------------------- #### isNumeric **Signature:** `_.isNumeric(value:Any)` A numeric is something that contains a numeric value, regardless of its type. It can be a string containing a numeric value, exponential notation, a `Number` object, etc. ```javascript _.isNumeric("14"); // => true _.isNumeric("fourteen"); // => false ``` -------------------------------------------------------------------------------- #### isOdd **Signature:** `_.isOdd(value:Any)` Checks whether the value is an odd number. ```javascript _.isOdd(3); // => true _.isOdd(2); // => false _.isOdd({}); // => false ``` -------------------------------------------------------------------------------- #### isPlainObject **Signature:** `_.isPlainObject(value:Any);` Checks whether the value is a "plain" object created as an object literal (`{}`) or explicitly constructed with `new Object()`. Instances of other constructors are **not** plain objects. ```javascript _.isPlainObject({}); // => true _.isPlainObject(new Date()); // => false _.isPlainObject([]); // => false ``` -------------------------------------------------------------------------------- #### isPositive **Signature:** `_.isPositive(value:Any)` Checks whether the value is a positive number. ```javascript _.isPositive(21); // => true _.isPositive(-3); // => false ``` -------------------------------------------------------------------------------- #### isSequential **Signature:** `_.isSequential(value:Any)` Checks whether the value is a sequential composite type (i.e. arrays and `arguments`). ```javascript _.isSequential(["Herodotus", "Thucidydes"); // => true _.isSequential(new Date); // => false ``` -------------------------------------------------------------------------------- #### isValidDate **Signature:** `_.isValidDate(value:Any)` Checks whether the value is a valid date. That is, the value is both an instance of `Date` and it represents an actual date. <span class="label label-danger">Warning:</span> This function does not verify whether the original input to `Date` is a real date. For instance, `new Date("02/30/2014")` is considered a valid date because `Date` coerces that into a representation of 03/02/2014. To validate strings representing a date, consider using a date/time library like [Moment.js.][momentjs] ```javascript _.isValidDate(new Date("January 1, 1900")); // => true _.isValidDate(new Date("The Last Great Time War")); // => false ``` -------------------------------------------------------------------------------- #### isZero **Signature:** `_.isZero(value:Any)` Checks whether the value is `0`. ```javascript _.isZero(0); // => true _.isZero("Pythagoras"); // => false ``` -------------------------------------------------------------------------------- [momentjs]:http://momentjs.com/