[perl] Powers!?! Where? - Tilted Forum Project Discussion Community

VF19 · 03-03-2004, 09:48 PM

How do I get a number to be multipied by its power in perl?
Im trying to solve this equation, y=c(1+r)[to the power of]t
but im stuck at where to multiply (1+r) by t.
Heres the script so far:

Quote:

#!usr/bin/perl;

use warnings;

print "You solve the y=c(1+r)t problem with this program. \n";

print "Enter c variable. \n";

my $cvar = <STDIN>;

print "Enter r variable. \n";

my $rvar = <STDIN>;

print "Enter t variable. \n";

my $tvar = <STDIN>;

chomp " $cvar , $rvar , $tvar ";

my $rvar1 = 1+r ;

my $r2tvar = $rvar1

Mephex · 03-03-2004, 09:50 PM

Quote:

Binary ** is the exponentiation operator. Note that it binds even more tightly than unary minus, so -2**4 is -(2**4), not (-2)**4. Note also that ** has right associativity, so:

$e = 2 ** 3 ** 4;
evaluates to 2 to the 81st power, not 8 to the 4th power.

The * (multiply) and / (divide) operators work exactly as you might expect, multiplying or dividing their two operands. Division is done in floating-point mode, unless integer mode in enabled (via use integer).

Hope that helps !

ni42 · 03-03-2004, 11:26 PM

somthing like this maybe?

Code:

$one = 2;
$two = 4;
$three = $one ** $two;
print $three;

ratbastid · 03-11-2004, 04:57 PM

Quote:

chomp " $cvar , $rvar , $tvar ";

That won't work. You're only passing one argument to chomp, and it's a string composed of each of your variables separated by a comma and a space. It's syntactically valid, but it does nothing. You're going to leave the return characters on the end of each of those $vars.

You should instead be getting your input like this:

chomp(my $cvar = <STDIN>);

That'll chomp DURING the assignment. You also save a line, which is important when you're playing Perl Golf.

And now that you know the ** operator, that formula should be a one-liner too.

03-03-2004, 11:26 PM	#3 (permalink)
ni42 Upright Location: BC, Canada	somthing like this maybe? Code: $one = 2; $two = 4; $three = $one ** $two; print $three; __________________ - 42 -