COCOS2D-JS Introductory One ([IsNaN () and Isfinite (), conversions between characters and number)

IsNaN (): Used to check if the parameter is a non-numeric value. Tip: Non-digital OH. (Not a number)
document.write (IsNaN (0))//return False
document.write (IsNaN (5-2))//return False
document.write (IsNaN ("Hello"))//return True
The isfinite (number) function is used to check whether its arguments are infinite.
Returns true if number is finite. Returns False if number is NaN (non-numeric) or infinity;

2): Characters:

Examples of simple operations for strings:
var a = "Cssrain";
var B = A.charat (a.length-1);  Intercepts the last character from string A. Output: N
var c = a.substring (0, 2); Intercept 1th, 2 characters from String A. Output: CS
var d = a.indexof (' s '); Finds the position where the first s appears from string A. Output: 1

3): The conversion between numbers and characters:

Numeric to Character:
var number_to_string = number + ""; Method 1: Add an empty string.
var number_to_string =string (number); Method 2: Use the string () function.
var number_to_string =number. ToString (); Method 3: Use the ToString () function.
Note: the ToString () method defaults to a 10 binary conversion.
If you want to use the 8 binary conversion You can write this: number. ToString (8);

character to number:
Var string_to_ The number = string – 0 ; //method 1:  the string minus 0.
Var string_to_number = number (String)  ; //Method 2: Use the number  () function.
Var string_to_number = parseint (String)  ; //Method 3: Use the parseint  () function.
cannot   with string+0 ;  in Method 1 This results in string concatenation instead of type conversions. The number function in the
method 2  is converted, which is more rigorous.
For example:
var a =  "19cssrain86";
Var b = number (a);   //output Nan.
If we use Method 3.
Var c = parseint (a);  //output  19
You can see that parseint () automatically ignores non-numeric portions.
parseint () takes only the integer part, ignoring the fractional part. The
Parsefloat () will also take the decimal part. Like the
and ToString (), the parseint has a binary, which is 10 binary by default.
If you want to use 8 binary, you can write this:  parseint (  077  , 8 ); //  output 63 = 7 *  8 + 7
When the character starts with 0, we must specify the   second parameter  , or JS may be converted to 8 binary.  

4): Definition of function:
Method 1: General definition
function Square (x) {
return x*x;
}
Method 2: Function Direct Volume definition
var square = function (x) {return x*x;} Recommended Use
Method 3: Construct the parameters
var square = new Function ("X", "Return x*x;"); Low efficiency

COCOS2D-JS Introductory One ([IsNaN () and Isfinite (), conversions between characters and number)