I came across a funny thing when the input to a calculation involving the exponential operator turned negativ.

To demonstrate - here is some code:

print "Power of calculation test\n";
print("line 1: ", -4**1.5, "\n");
print("line 2: ", (-4)**1.5, "\n");
print("line 3: ", 1/(-4)**1.5, "\n");
print("line 4: ", 3 + (-4)**1.5, "\n");

[download]
The output looked like this:

Power of calculation test
line 1: -8
line 2: 0
line 3: 0
line 4: 0

[download]

So, the line 1 output is probably explained by precedence.

However, if line 2 is a permissible operation - how does it get to zero?

And why (line 3) can I use the result as a divisor without Perl complaining about division by zero or add 3 and still get zero?

It cost me a few hours to find why my numbers did not add up - shouldn't (-4)**1.5 be an illegal statement?

Appreciate your wisdom...

In reply to Strange Logic in Power of arithmetic by stephanm

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