# isBetween > Test if a value is between two values.
## Usage ```javascript var isBetween = require( '@stdlib/assert/is-between' ); ``` #### isBetween( value, a, b\[, left, right] ) Tests if a `value` is between two values `a` (left comparison value) and `b` (right comparison value). ```javascript var bool = isBetween( 4, 3, 5 ); // returns true bool = isBetween( 2, 3, 5 ); // returns false bool = isBetween( 6, 3, 5 ); // returns false ``` By default, the function assumes that `a` and `b` are inclusive. ```javascript var bool = isBetween( 3, 3, 5 ); // returns true bool = isBetween( 3, 3, 5, 'closed', 'closed' ); // returns true bool = isBetween( 5, 3, 5 ); // returns true bool = isBetween( 5, 3, 5, 'closed', 'closed' ); // returns true ``` To make `a` and/or `b` exclusive, set the respective arguments to `'open'`. ```javascript var bool = isBetween( 3, 3, 5, 'open', 'closed' ); // returns false bool = isBetween( 5, 3, 5, 'closed', 'open' ); // returns false ```
## Notes - If `a` and `b` are inclusive, the comparison is equivalent to ```text a <= v <= b ``` - If `a` is exclusive and `b` is inclusive, the comparison is equivalent to ```text a < v <= b ``` - If `a` is inclusive and `b` is exclusive, the comparison is equivalent to ```text a <= v < b ``` - If `a` and `b` are exclusive, the comparison is equivalent to ```text a < v < b ``` - If provided non-numeric values, comparisons are performed according to lexicographic order.
## Examples ```javascript var randu = require( '@stdlib/random/base/randu' ); var round = require( '@stdlib/math/base/special/round' ); var isBetween = require( '@stdlib/assert/is-between' ); var bool; var a; var b; var v; var i; for ( i = 0; i < 100; i++ ) { a = round( (randu()*10.0) + 5.0 ); b = round( (randu()*10.0) + 15.0 ); v = round( randu()*25.0 ); bool = isBetween( v, a, b, 'open', 'closed' ); console.log( '%d < %d <= %d: %s', a, v, b, bool.toString() ); } ```