# FLOAT32_EXPONENT_MASK
> Mask for the exponent of a [single-precision floating-point number][ieee754].
## Usage
```javascript
var FLOAT32_EXPONENT_MASK = require( '@stdlib/constants/float32/exponent-mask' );
```
#### FLOAT32_EXPONENT_MASK
Mask for the exponent of a [single-precision floating-point number][ieee754].
```javascript
// 0x7f800000 = 2139095040 => 0 11111111 00000000000000000000000
var bool = ( FLOAT32_EXPONENT_MASK === 0x7f800000 );
// returns true
```
## Examples
```javascript
var toWord = require( '@stdlib/number/float32/base/to-word' );
var FLOAT32_EXPONENT_MASK = require( '@stdlib/constants/float32/exponent-mask' );
var x = 11.5;
var w = toWord( x ); // 0 10000010 01110000000000000000000
// returns 1094189056
// Mask off all bits except for the exponent bits:
var out = w & FLOAT32_EXPONENT_MASK; // 0 10000010 00000000000000000000000
// returns 1090519040
// Mask on the exponent bits and leave other bits unchanged:
out = w | FLOAT32_EXPONENT_MASK; // 0 11111111 01110000000000000000000
// returns 2142765056
```
* * *
## C APIs
### Usage
```c
#include "stdlib/constants/float32/exponent_mask.h"
```
#### STDLIB_CONSTANT_FLOAT32_EXPONENT_MASK
Macro for the mask for the exponent of a [single-precision floating-point number][ieee754].
[ieee754]: https://en.wikipedia.org/wiki/IEEE_754-1985
[@stdlib/constants/float32/sign-mask]: https://github.com/stdlib-js/constants/tree/main/float32/sign-mask
[@stdlib/constants/float32/significand-mask]: https://github.com/stdlib-js/constants/tree/main/float32/significand-mask
[@stdlib/constants/float32/abs-mask]: https://github.com/stdlib-js/constants/tree/main/float32/abs-mask