2.1 KiB
2.1 KiB
Constant Function
Constant function.
A constant function is a function
whose output value is the same for every input value.
Usage
var constantFunction = require( '@stdlib/utils/constant-function' );
constantFunction( x )
Returns a constant function which always returns x
.
var fcn = constantFunction( 'beep' );
// returns <Function>
var v = fcn();
// returns 'beep'
v = fcn();
// returns 'beep'
Notes
-
When provided an object reference, the returned
function
always returns the same reference.var obj = {}; var fcn = constantFunction( obj ); var bool = ( fcn() === obj ); // returns true
Examples
var constantFunction = require( '@stdlib/utils/constant-function' );
var bool;
var fcn;
var arr;
var v;
var i;
fcn = constantFunction( 3.14 );
for ( i = 0; i < 10; i++ ) {
v = fcn();
// returns 3.14
}
arr = [ 1, 2, 3 ];
fcn = constantFunction( arr );
for ( i = 0; i < 10; i++ ) {
v = fcn();
bool = ( v === arr );
// returns true
}