A switch construct is more easily translated into a jump (or branch) table. This can make switch statements much more efficient than if-else when the case labels are close together. The idea is to place a bunch of jump instructions sequentially in memory and then add the value to the program counter. This replaces a … Read more
You can use the “pattern-match” operator ~=: if 200 … 299 ~= statusCode { print(“success”) } Or a switch-statement with an expression pattern (which uses the pattern-match operator internally): switch statusCode { case 200 … 299: print(“success”) default: print(“failure”) } Note that ..< denotes a range that omits the upper value, so you probably want … Read more
At the very lowest level (in the hardware), yes, ifs are expensive. In order to understand why, you have to understand how pipelines work. The current instruction to be executed is stored in something typically called the instruction pointer (IP) or program counter (PC); these terms are synonymous, but different terms are used with different … Read more
The problem with the first version is that if you go back and add a second statement to the if or else clauses without remembering to add the curly braces, your code will break in unexpected and amusing ways. Maintainability-wise, it’s always smarter to use the second form. EDIT: Ned points this out in the … Read more
Angularjs (versions below 1.1.5) does not provide the if/else functionality . Following are a few options to consider for what you want to achieve: (Jump to the update below (#5) if you are using version 1.1.5 or greater) 1. Ternary operator: As suggested by @Kirk in the comments, the cleanest way of doing this would … Read more
Whatever is in the parentheses will be interpreted as a boolean value, either true or false. If it’s a character, then in most programming languages, this interpretation happens via two steps: the character is interpreted as an integer, usually its ASCII value the integer is interpreted as a boolean (usually false for 0 and true … Read more