JavaScript programming style

1. Brackets
Rule 1: braces at the beginning of the block. Do not start another line.
2. parentheses
In JavaScript, parentheses have two functions: one for calling a function and the other for a combination of different values. We can use spaces to distinguish the two different brackets.
Rule 2: When a function is called, there is no space between the function name and the left bracket.
Rule 3: there is no space between the function name and the parameter Sequence
Rule 4: there is a space between all other syntax elements and the left parenthesis.
3. semicolon
In most cases, if you omit the semicolon, JavaScript will automatically add
Rule 5: Do not skip the last semicolon
4. With statement
With statement can be reduced Code But may cause confusion.
Rule 6: Do not use the with statement
5. Equal and strictly equal
The equality operator automatically converts the variable type, resulting in many unexpected situations.
Rule 7: Do not use "equal" (=), only use the "strict equal" (=) Operator
6. Statement Merging
Rule 8: Do not merge statements for different purposes into one row.
7. Variable Declaration
Javascript automatically promotes the variable life to the header of the code block.
Rule 9: all variables are stored in the function header.
Rule 10: All functions are defined before use.
8. Global Variables
Global variables are readable and writable for any code block. This is not applicable to code modularization and reuse.
Rule 11: Avoid using global variables. If you have to use them, use uppercase letters.
9. New command
Javascript uses the new command to generate a new object from the constructor.
VaR o = new myobject ();
In this way, the question is: Once you forget to add new, the this keyword in myobject will point to the global object. As a result, all the variables bound to this will be programmed with global variables.
Rule 12: Use the object. Create () command
Rule 13: name of the constructor. uppercase letters are used. Other function names must be in lowercase.
10. Auto-increment and auto-subtraction Operators
The auto-increment and auto-increment operators are placed before or after the variables. The return values are different and are prone to errors.
All ++ operators can be replaced by "+ = 1 ".
Rule 14: Do not use the auto-increment and auto-increment operators, instead of the + = and-= operators.
11. Block
If the code body for loop and judgment has only one line, JavaScript allows this block to omit braces.
Rule 15: Always use braces to represent Blocks