Javascript [Electronic resources] : The Definitive Guide (4th Edition) نسخه متنی

Availability

DOM Level 2 CSS

Synopsis

float getFloatValue(unsigned short unitType)
throws DOMException;

Arguments

unitType

One of the CSSPrimitiveValue type constants that specifies the
desired units for the returned value.

Returns

The floating-point numeric value of this CSSPrimitiveValue, expressed
in the specified units.

Throws

This method throws a DOMException with a code of
INVALID_ACCESS_ERR if this CSSPrimitiveValue holds
a non-numeric value, or if the value cannot be converted to the
requested type of units. (See the next section for more about unit
conversion.)

Description

For CSSPrimitiveValue objects that hold numeric values, this method
converts those values to the specified units and returns the
converted values.

Only certain types of unit conversions are allowed. Lengths may be
converted to lengths, angles to angles, times to times, and
frequencies to frequencies. Obviously, however, a length measured in
millimeters cannot be converted to a frequency measured in kilohertz.
Also, not all lengths can be converted. Relative lengths (lengths
measured in ems, exs, or pixels) can be converted to other relative
lengths but cannot be converted to absolute lengths. Similarly,
absolute lengths cannot be converted to relative lengths. Finally,
percentage values cannot be converted to any other unit type, except
for color percentage values, which express a percentage of 255 and
can be converted to the CSS_NUMBER type.