Javascripts .call() and .apply() methods allow you to set the context for a function. var myfunc = function(){ alert(this.name); }; var obj_a = { name: “FOO” }; var obj_b = { name: “BAR!!” }; Now you can call: myfunc.call(obj_a); Which would alert FOO. The other way around, passing obj_b would alert BAR!!. The difference between … Read more
As Fermin said, a variable in the global scope should be accessible to all scripts loaded after it is declared. You could also use a property of window or (in the global scope) this to get the same effect. // first.js var colorCodes = { back : “#fff”, front : “#888”, side : “#369” }; … Read more
echo -e $lines | while read line … done The while loop is executed in a subshell. So any changes you do to the variable will not be available once the subshell exits. Instead you can use a here string to re-write the while loop to be in the main shell process; only echo -e … Read more
Python treats variables in functions differently depending on whether you assign values to them from inside or outside the function. If a variable is assigned within a function, it is treated by default as a local variable. Therefore, when you uncomment the line, you are trying to reference the local variable c before any value … Read more
That’s only a convention. The Javascript language does not give any special meaning to identifiers starting with underscore characters. That said, it’s quite a useful convention for a language that doesn’t support encapsulation out of the box. Although there is no way to prevent someone from abusing your classes’ implementations, at least it does clarify … Read more
Here is what is going on. First, the only global variables Python really has are module-scoped variables. You cannot make a variable that is truly global; all you can do is make a variable in a particular scope. (If you make a variable inside the Python interpreter, and then import other modules, your variable is … Read more
No – but technically there is a work-around (not that i’d actually use it unless forced to): for(struct { int a; char b; } s = { 0, ‘a’ } ; s.a < 5 ; ++s.a) { std::cout << s.a << ” ” << s.b << std::endl; }
UPDATE: This question was the subject of my blog in September 2014. Thanks for the great question! There is considerable debate on this question even within the compiler team itself. First off, it’s wise to understand the rules. A public member of a class or struct is a member that is accessible to anything that … Read more
This is because, even though Var1 exists, you’re also using an assignment statement on the name Var1 inside of the function (Var1 -= 1 at the bottom line). Naturally, this creates a variable inside the function’s scope called Var1 (truthfully, a -= or += will only update (reassign) an existing variable, but for reasons unknown … Read more
See this article on alistapart.com. (Ed: The article has been updated since originally linked) self is being used to maintain a reference to the original this even as the context is changing. It’s a technique often used in event handlers (especially in closures). Edit: Note that using self is now discouraged as window.self exists and … Read more