psychology dector

In languages whose syntax is derived from C (e.g.: C ← C++ ← Java ← JavaScript), two brace styles are most common: Allman style and 1TBS. Allman style If a statement [1] contains a block, that block is considered as somewhat separate from the header of the statement: its opening brace is in a line of its own, at the same indentation level as the head. For example: function foo(x, y, z) { if (x) { a(); } else { b(); c(); } } 1TBS (One True Brace Style) Here, a block is more closely associated with the header of its statement, it starts after it, in the same line. For example: function foo(x, y, z) { if (x) { a(); } else { b(); c(); } } 1TBS is a variant of the (older) K&R (Kernighan and Ritchie) style. In K&R style, functions are written in Allman style and braces are omitted where they are not necessary, e.g. around single-stateme...

This blog post mentions three rules that are commonly given for using var statements. And then tells you when you can break them. To make things easier to understand, I somewhat disparagingly call the rules “conventional wisdom” and breaking the rules “unconventional wisdom”. But I will also explain why the rules have been created in the first place. For this blog post, you should know how JavaScript’s function-scoped var declarations work. Consult [1] if you don’t. Three rules you can break Rule to break: Don’t put a var statement inside a block Conventional wisdom in JavaScript tells you that the following code is bad: // Unconventional wisdom function foo(x, y) { if (x > y) { var tmp = x; x = y; y = tmp; } ... } Point: Looking at the code, one might think that the variable tmp only existed inside the then-block of the if statement. What really happens is that the variable declaration is hoisted – the d...