signbit

Return a boolean indicating if the sign bit for a double-precision floating-point number is on (true) or off (false).

Usage

var signbit = require( '@stdlib/number/float64/base/signbit' );

signbit( x )

Returns a boolean indicating if the sign bit for a double-precision floating-point number is on (true) or off (false).

var bool = signbit( 4.0 );
// returns false

bool = signbit( -9.14e-307 );
// returns true

bool = signbit( 0.0 );
// returns false

bool = signbit( -0.0 );
// returns true

Examples

var randu = require( '@stdlib/random/base/randu' );
var signbit = require( '@stdlib/number/float64/base/signbit' );

var sign;
var x;
var i;

for ( i = 0; i < 100; i++ ) {
    x = ( randu()*100.0 ) - 50.0;
    sign = signbit( x );
    sign = ( sign ) ? 'true' : 'false';
    console.log( 'x: %d. signbit: %s.', x, sign );
}