JavaScript Tutorial/Number Data Type/Float
Содержание
Adding the float point numbers together
<source lang="javascript">
<html> <head> <title>GoodAdd</title> </head> <body> <script> var meal; meal = 123.45; meal = eval(meal); var tip = meal * .15; var total = meal + tip; alert ("the meal is $" + meal); alert ("the tip is $" + tip); alert ("Total bill: $" + total); </script> </body> </html></source>
Floating-Point Numbers
Floating-point numbers can contain fractional parts.
Floating-point numbers can use exponential notation for added precision.
Floating-point numbers are made up of a decimal integer followed by a period (.) and the fractional portion of the number.
Exponential notation can be used by adding an e or E to the end of a floating-point number followed by a decimal integer that does not exceed 3 digits.
Use 1.0 not 1.
<source lang="javascript">
var fNum = 1.0;</source>
Floating-point values can be represented using e-notation
In e-notation, a number is represented by digits, followed by an e or an E, followed by the number of times to multiply it by 10.
<source lang="javascript">
var fNum = 3.125e7;</source>
This notation represents the number 31250000.
You can get this value by converting the e-notation to a calculation: 3.125 * 10^7.
0.00000000000000003 can be written as 3e-17.
Here, 10 is raised to the -17 power.
By default, JavaScript converts any floating-point number with six or more leading zeros into e-notation.
Floating-point values are stored in a 64-bit IEEE 754 format.
Decimal values can have up to 17 decimal places.
After that, the values are truncated.
float point value
<source lang="javascript">
<HTML> <BODY> <SCRIPT language="JavaScript">
</SCRIPT> </BODY> </HTML></source>
