# From Binary String
> Create a [single-precision floating-point number][ieee754] from an [IEEE 754 literal bit representation][@stdlib/number/float32/base/to-binary-string].
## Usage
```javascript
var fromBinaryStringf = require( '@stdlib/number/float32/base/from-binary-string' );
```
#### fromBinaryStringf( bstr )
Creates a [single-precision floating-point number][ieee754] from an [IEEE 754 literal bit representation][@stdlib/number/float32/base/to-binary-string].
```javascript
var bstr = '01000000100000000000000000000000';
var v = fromBinaryStringf( bstr );
// returns 4.0
bstr = '01000000010010010000111111011011';
v = fromBinaryStringf( bstr );
// returns ~3.14
bstr = '11111111011011000011101000110011';
v = fromBinaryStringf( bstr );
// returns ~-3.14e+38
```
The function handles [subnormals][subnormals].
```javascript
var bstr = '10000000000000000000000000010110';
var val = fromBinaryStringf( bstr );
// returns ~-3.08e-44
bstr = '00000000000000000000000000000001';
val = fromBinaryStringf( bstr );
// returns ~1.40e-45
```
The function handles special values.
```javascript
var bstr = '00000000000000000000000000000000';
var val = fromBinaryStringf( bstr );
// returns 0.0
bstr = '10000000000000000000000000000000';
val = fromBinaryStringf( bstr );
// returns -0.0
bstr = '01111111110000000000000000000000';
val = fromBinaryStringf( bstr );
// returns NaN
bstr = '01111111100000000000000000000000';
val = fromBinaryStringf( bstr );
// returns Infinity
bstr = '11111111100000000000000000000000';
val = fromBinaryStringf( bstr );
// returns -Infinity
```
## Examples
```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 toBinaryStringf = require( '@stdlib/number/float32/base/to-binary-string' );
var fromBinaryStringf = require( '@stdlib/number/float32/base/from-binary-string' );
var frac;
var sign;
var exp;
var b;
var x;
var y;
var i;
// Convert random numbers to IEEE 754 literal bit representations and then convert them back...
for ( i = 0; i < 100; i++ ) {
if ( randu() < 0.5 ) {
sign = -1.0;
} else {
sign = 1.0;
}
frac = randu() * 10.0;
exp = round( randu()*100.0 );
if ( randu() < 0.5 ) {
exp = -exp;
}
x = sign * frac * pow( 2.0, exp );
x = toFloat32( x );
b = toBinaryStringf( x );
y = fromBinaryStringf( b );
console.log( '%d => %s => %d', x, b, y );
console.log( x === y );
}
```
[ieee754]: https://en.wikipedia.org/wiki/IEEE_754-1985
[subnormals]: https://en.wikipedia.org/wiki/Denormal_number
[@stdlib/number/float32/base/to-binary-string]: https://www.npmjs.com/package/@stdlib/number/tree/main/float32/base/to-binary-string