Return an integer corresponding to the unbiased exponent of a single-precision floating-point number.
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> Return an integer corresponding to the unbiased exponent of a [single-precision floating-point number][ieee754].
``bash`
npm install @stdlib/number-float32-base-exponent
`javascript`
var exponentf = require( '@stdlib/number-float32-base-exponent' );
#### exponentf( x )
Returns an integer corresponding to the unbiased exponent of a [single-precision floating-point number][ieee754].
`javascript
var toFloat32 = require( '@stdlib/number-float64-base-to-float32' );
var exp = exponentf( toFloat32( 3.14e34 ) ); // => 2^114 ~ 2.08e34
// returns 114
exp = exponentf( toFloat32( 3.14e-34 ) ); // => 2^-112 ~ 1.93e-34
// returns -112
exp = exponentf( toFloat32( -3.14 ) );
// returns 1
exp = exponentf( 0.0 );
// returns -127
exp = exponentf( NaN );
// returns 128
`
`javascript
var randu = require( '@stdlib/random-base-randu' );
var round = require( '@stdlib/math-base-special-round' );
var pow = require( '@stdlib/math-base-special-pow' );
var toFloat32 = require( '@stdlib/number-float64-base-to-float32' );
var exponentf = require( '@stdlib/number-float32-base-exponent' );
var frac;
var exp;
var x;
var e;
var i;
// Generate random numbers and extract their exponents...
for ( i = 0; i < 100; i++ ) {
frac = randu() * 10.0;
exp = round( randu()*44.0 ) - 22;
x = frac * pow( 10.0, exp );
x = toFloat32( x );
e = exponentf( x );
console.log( 'x: %d. unbiased exponent: %d.', x, e );
}
`
*
`c`
#include "stdlib/number/float32/base/exponent.h"
#### stdlib_base_float32_exponent( x )
Returns an integer corresponding to the unbiased exponent of a [single-precision floating-point number][ieee754].
`c
#include
int32_t out = stdlib_base_float32_exponent( 3.14f );
`
The function accepts the following arguments:
- x: [in] float input value.
`c`
int32_t stdlib_base_float32_exponent( const float x );
`c
#include "stdlib/number/float32/base/exponent.h"
#include
#include
#include
int main( void ) {
float x[] = { 4.0f, 0.0f, -0.0f, 1.0f, -1.0f, 3.14f, -3.14f, 1.0e38f, -1.0e38f, 1.0f/0.0f, -1.0f/0.0f, 0.0f/0.0f };
int32_t out;
int i;
for ( i = 0; i < 12; i++ ) {
out = stdlib_base_float32_exponent( x[ i ] );
printf( "%f => out: %" PRId32 "\n", x[ i ], out );
}
}
`
*
- [@stdlib/number-float64/base/exponent][@stdlib/number/float64/base/exponent]: return an integer corresponding to the unbiased exponent of a double-precision floating-point number.
*
This package is part of [stdlib][stdlib], a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.
For more information on the project, filing bug reports and feature requests, and guidance on how to develop [stdlib][stdlib], see the main project [repository][stdlib].
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---
See [LICENSE][stdlib-license].
Copyright © 2016-2026. The Stdlib [Authors][stdlib-authors].
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[stdlib]: https://github.com/stdlib-js/stdlib
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[umd]: https://github.com/umdjs/umd
[es-module]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules
[deno-url]: https://github.com/stdlib-js/number-float32-base-exponent/tree/deno
[deno-readme]: https://github.com/stdlib-js/number-float32-base-exponent/blob/deno/README.md
[umd-url]: https://github.com/stdlib-js/number-float32-base-exponent/tree/umd
[umd-readme]: https://github.com/stdlib-js/number-float32-base-exponent/blob/umd/README.md
[esm-url]: https://github.com/stdlib-js/number-float32-base-exponent/tree/esm
[esm-readme]: https://github.com/stdlib-js/number-float32-base-exponent/blob/esm/README.md
[branches-url]: https://github.com/stdlib-js/number-float32-base-exponent/blob/main/branches.md
[stdlib-license]: https://raw.githubusercontent.com/stdlib-js/number-float32-base-exponent/main/LICENSE
[ieee754]: https://en.wikipedia.org/wiki/IEEE_754-1985
[@stdlib/number/float64/base/exponent]: https://www.npmjs.com/package/@stdlib/number-float64-base-exponent