From cd7ed4f9f9590f82acf953bba8d6032e1f62fa0c Mon Sep 17 00:00:00 2001 From: Levi Bostian Date: Fri, 5 Sep 2014 20:47:18 -0500 Subject: Couple changes to C to close https://github.com/adambard/learnxinyminutes-docs/pull/594 --- c.html.markdown | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'c.html.markdown') diff --git a/c.html.markdown b/c.html.markdown index 79b7aec7..cbb6d289 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -4,6 +4,7 @@ filename: learnc.c contributors: - ["Adam Bard", "http://adambard.com/"] - ["Árpád Goretity", "http://twitter.com/H2CO3_iOS"] + - ["Jakub Trzebiatowski", "http://cbs.stgn.pl"] --- @@ -175,6 +176,9 @@ int main() { i2 * i1; // => 2 i1 / i2; // => 0 (0.5, but truncated towards 0) + // You need to cast at least one integer to float to get a floating-point result + (float)i1 / i2 // => 0.5f + i1 / (double)i2 // => 0.5 // Same with double f1 / f2; // => 0.5, plus or minus epsilon // Floating-point numbers and calculations are not exact @@ -194,9 +198,11 @@ int main() { 2 >= 2; // => 1 // C is not Python - comparisons don't chain. - // WRONG: - //int between_0_and_2 = 0 < a < 2; - // Correct: + // Warning: The line below will compile, but it means `(0 < a) < 2`. + // This expression is always true, because (0 < a) could be either 1 or 0. + // In this case it's 1, because (0 < 1). + int between_0_and_2 = 0 < a < 2; + // Instead use: int between_0_and_2 = 0 < a && a < 2; // Logic works on ints -- cgit v1.2.3