ternary-operator

I'm new to Python and I'm trying to use ternary opertor which has this format (I think so) value_true if <test> else value_false Here's a snippet of code: expanded = set() while not someExpression: continue if currentState in expanded else expanded.push(currentState) # some code here But Python doesn't like it and says: SyntaxError: invalid syntax (pointed to if) How to fix it? Ternary operation in python using for expression , not statements . Expression is something that has value. Example: result = foo() if condition else (2 + 4) # ^^^^^ ^^^^^^^ # expression expression For statements (code

Possible Duplicate: Problem with PHP ternary operator I was reading up a bit on PHP in this article , and I stopped for a while to consider one of his gripes. I can't figure out how on earth PHP comes to the result that it does. Unlike (literally!) every other language with a similar operator, ?: is left associative. So this: $arg = 'T'; $vehicle = ( ( $arg == 'B' ) ? 'bus' : ( $arg == 'A' ) ? 'airplane' : ( $arg == 'T' ) ? 'train' : ( $arg == 'C' ) ? 'car' : ( $arg == 'H' ) ? 'horse' : 'feet' ); echo $vehicle; prints horse. What logical path does PHP follow that results in 'horse' being

I am following along with the Rails 3 in Action book, and it is talking about override to_s in the model. The code is the following: def to_s "#{email} (#{admin? ? "Admin" : "User"})" end I know that in Ruby you can display a value inside double quotes by the "#{value}" , but what's up with the double question marks? It's string interpolation . "#{email} (#{admin? ? "Admin" : "User"})" is equivalent to email.to_s + " (" + (admin? ? "Admin" : "User") + ")" that is email.to_s + " (" + if admin? then "Admin" else "User" end + ")" As a result of being enclosed in quotes, in this context Admin and

gcc 4.7.2 c89 Hello, I am getting the following warning: pointer/integer type mismatch in conditional expression I am compiling with the following CFLAGS -Wall -Wextra fprintf(stderr, "'Failed to open file' Error [ %s ]\n", (errno == 0) ? "None" : strerror(errno)); The program runs ok, but I can't see that the warning is all about. Both "None" and strerror(errno) return a string and not Integer value. And I am comparing errno number to zero. Many thanks for any suggestions, Check whether you have included <string.h> header. If not, the return value of strerror may be considered as an integer

I have a code block like this: /*global MYAPP: true*/ var MYAPP = MYAPP || {}; JSLint highlights "MYAPP" after equal sign with message "MYAPP used out of scope". What's wrong with that? If you use var then you are declaring a local variable. If you do MYAPP || {} then you are typically trying to set a default value for a global variable, or for a variable declared earlier. What is the scope of MYAPP supposed to be? If it is global, then something like MYAPP = window.MYAPP || {}; window. stops it from complaining that it is undefined If it is not global but declared earlier, then MYAPP = MYAPP

Given two implementations of Comparison methods: // compares by Key... private static int CompareByKey(KeyValuePair<int, string> x, KeyValuePair<int, string> y) { return x.Key.CompareTo(y.Key); } // compares by Value... private static int CompareByValue(KeyValuePair<int, string> x, KeyValuePair<int, string> y) { return x.Value.CompareTo(y.Value); } Why wouldn't the following conditional operator code block compile: Comparison<KeyValuePair<int, string>> sortMethod; sortMethod = isSortByActualValue ? CompareByKey : CompareByValue; Compiler error: "Type of conditional expression cannot be