# Clamp Index > Restrict an index to the interval `[0,max]`.
## Usage ```javascript var clampIndex = require( '@stdlib/ndarray/base/clamp-index' ); ``` #### clampIndex( idx, max ) Restricts an index to the interval `[0,max]`. ```javascript var idx = clampIndex( 2, 10 ); // returns 2 idx = clampIndex( -5, 10 ); // returns 0 idx = clampIndex( 15, 10 ); // returns 10 ```
## Examples ```javascript var discreteUniform = require( '@stdlib/random/base/discrete-uniform' ); var clampIndex = require( '@stdlib/ndarray/base/clamp-index' ); var idx; var out; var i; for ( i = 0; i < 100; i++ ) { idx = discreteUniform( -20, 20 ); out = clampIndex( idx, 10 ); console.log( '%d => [%d,%d] => %d', idx, 0, 10, out ); } ```