Data type conversions in JavaScript

Convert to Number:

parseint (); Convert to integer value, starting from subscript 0, if the numeric type continues until a non-numeric value is encountered, the preceding integer values are returned;
The decimal point is not valid and returns Nan if 0 is non-numeric;
Converting an empty string returns Nan;

Can be converted to a different binary, such as Var a=parseint ("123", 2);//return result is 2 binary

Parsefloat (); Convert to decimal, starting with subscript 0, only 10 binary form; If there is a second decimal point, the second decimal point is invalid and all is discarded.
Returns the front face value, which returns Nan if 0 starts with a non-numeric value, ignores the leading 0, such as: Var b=parsefloat (010);//10;

To force type conversions:

Boolean (); Any non-empty string is true; any non-0 numeric value (including infinity) is true; Any object is true, NULL is false;undefined can only be false;

Number (); If Boolean, True and false convert to 1/0;null convert to 0;undefined to Nan;

String: Contains only numbers (including positive, negative sign) converted to 10 decimal, leading 0 ignored; if floating-point numbers are converted to floating-point values, leading 0 is ignored;

Contains 16 binary, converted to a decimal value of the same size, or 0 if NULL, if the conversion to Nan is included in the preceding several;

Object: Invokes the ValueOf () method of the object and then transforms the return value according to the preceding rule, or ToString () If the result is Nan;

The preceding rule transformation returns a string value.

Number (); parseint (); The difference is that if there is a non-number behind the preceding number in the string, the former returns Nan, and the latter returns numbers that are not in front of the number;

Handles an empty string, which returns 0, while the latter returns Nan;

String (), numeric, Boolean, String value, object has the Tosting () method, null, undefined not, so you cannot use the same ToString () method to convert this

2 kinds, otherwise it will error, this is the difference between the string () and ToString ();

Conversion rules:

If the value has the ToString () method, the method is called to return the corresponding result; "NULL" is returned if null, and "undefined" is returned for undefined;

Data type conversions in JavaScript