one , 1.2.toFixed (2)
The floating-point number is rounded to set the numeric value of the specified decimal place
two , 2.toFixed (2)
Integer, but in JS it is considered an object name so that it cannot be used
Third, "1.2". ToFixed (2)
Because the Tofixed method is for number type, the string type cannot be used even if it can be converted to numbers.
Four, Var a=1;a.tofixed (2);
Constructs an integer object, you can call the
Http://www.w3school.com.cn/jsref/jsref_tofixed.asp
The following is an introduction in W3school:
ToFixed () This method is for the number object (the numeric object is the wrapper object for the original value).
The ToFixed () method rounds numbers to a number that specifies the number of decimal digits.
Numberobject.tofixed (num)
Parameters |
Description |
Num |
Necessary. Specifies the number of decimal places, which are values between 0 and 20, including 0 and 20, and some implementations can support a larger range of values. If this argument is omitted, 0 will be used instead. |
return value
Returns a string representation of numberobject, with no exponential notation, and a fixed num digit number after the decimal point. If necessary, the number is rounded, or it can be topped with 0 so that it reaches the specified length. If NUM is greater than le+21, the method only calls Numberobject.tostring () and returns the string represented by exponential notation.
Thrown
Throws an exception rangeerror when NUM is too small or too large. A value between 0 and 20 does not throw the exception. Some implementations support values in a larger range or a smaller range.
The TypeError exception is thrown when the object calling the method is not number.
Number of decimal digits reserved in JS