La función wantarray() en Perl devuelve True si la subrutina que se está ejecutando actualmente espera devolver un valor de lista y false si está buscando un valor escalar.
Sintaxis: wantarray()
Devuelve: verdadero para el valor de la lista y falso para los valores escalares
Ejemplo 1:
#!/usr/bin/perl -w
# Subroutine to call wantarray() function
sub geeks
{
return(wantarray() ? ("Geeks", "For", "Geeks") : 1);
}
# Calling the subroutine
# in scalar and array context
$value = geeks();
@value = geeks();
# Printing the values in both contexts
print("Value in Scalar context: $value\n");
print("Value in List Context: @value");
Producción:
Value in Scalar context: 1 Value in List Context: Geeks For Geeks
Ejemplo 2:
#!/usr/bin/perl -w
# Subroutine to call wantarray() function
sub geeks
{
if(wantarray())
{
# Addition of two numbers when
# wantarray() function is called
# in list context
$c = $a + $b;
}
else
{
# When wantarray() is called
# in Scalar context
return 1;
}
}
# Driver Code
$a = 10; $b = 20; $c = 0;
# Calling Subroutine in scalar and list contexts
$value = geeks($a, $b);
@value = geeks($a, $b);
# Printing values in both the contexts
print("Value when called in Scalar context: $value\n");
print("Value when called in List Context: @value");
Producción:
Value when called in Scalar context: 1 Value when called in List Context: 30