# j0 > Compute the [Bessel function of the first kind][bessel-first-kind] of order zero.
The [Bessel function of the first kind][bessel-first-kind] of order zero is defined as
Bessel function of the first kind of order zero
## Usage ```javascript var j0 = require( '@stdlib/math/base/special/besselj0' ); ``` #### j0( x ) Compute the [Bessel function of the first kind][bessel-first-kind] of order zero at `x`. ```javascript var v = j0( 0.0 ); // returns 1.0 v = j0( 1.0 ); // returns ~0.765 v = j0( Infinity ); // returns 0.0 v = j0( -Infinity ); // returns 0.0 v = j0( NaN ); // returns NaN ```
## Examples ```javascript var randu = require( '@stdlib/random/base/randu' ); var j0 = require( '@stdlib/math/base/special/besselj0' ); var x; var i; for ( i = 0; i < 100; i++ ) { x = randu() * 10.0; console.log( 'j0(%d) = %d', x, j0( x ) ); } ```