## Usage ```javascript var contains = require( '@stdlib/assert/contains' ); ``` #### contains( val, searchValue\[, position] ) Tests if `val` contains a search value. When `val` is a `string`, the function checks whether the characters of a search string are found in the input string. ```javascript var v = contains( 'Hello World', 'World' ); // returns true ``` When `val` is an `array-like` object, but not a `string`, the function checks whether the input value contains an element strictly equal to the specified search value. ```javascript var arr = [ null, NaN, 2, 'abc', {} ]; var v = contains( arr, NaN ); // NaNs are considered equal // returns true v = contains( arr, {} ); // returns false v = contains( arr, 'ab' ); // returns false ``` Search is case-sensitive. ```javascript var v = contains( 'Hello World', 'world' ); // returns false ``` To start searching at a specified index, provide a `position` argument. ```javascript var v = contains( 'Hello World', 'Hello', 6 ); // returns false v = contains( [ true, NaN, false ], true, 1 ); // returns false ``` If not provided an `array-like` object, the function throws an error. ```javascript var v = contains( false, 'abc' ); // throws ``` If not provided an integer-valued `position` argument, the function throws an error. ```javascript var v = contains( 'hello', 'e', 2.5 ); // throws ```

* * * ## Notes - For `strings`, the function is modeled after [String.prototype.includes][mdn-includes], part of the ECMAScript 6 specification. This function is different from a call to `String.prototype.includes.call` insofar as type-checking is performed for all arguments. - The function does **not** distinguish between positive and negative zero. - If `position < 0`, the search is performed for the entire input array or string.

## Examples ```javascript var contains = require( '@stdlib/assert/contains' ); var bool = contains( 'last man standing', 'stand' ); // returns true bool = contains( [ 1, 2, 3, 4 ], 2 ); // returns true bool = contains( 'presidential election', 'president' ); // returns true bool = contains( [ NaN, 2, 3, 4 ], NaN ); // returns true bool = contains( 'javaScript', 'js' ); // returns false bool = contains( 'Hidden Treasures', '' ); // returns true ```