Java Tutorial/Data Type/Float Point Data Type
Содержание
Applying the modulus operator, %, to floating-point values
<source lang="java">
public class MainClass{
public static void main(String[] arg){
double a = 2.4;
double b = 0.2;
System.out.println( a % b );
}
}</source>
0.1999999999999998
Floating-Point Calculations
The four arithmetic operators: +, -, *, /.
<source lang="java">
public class MainClass {
public static void main(String[] args) {
double numA = 50.0E-1; // 5.0
double numB = 1.0E1; // 10.0
double averageC = 0.0;
averageC = (numA + numB) / 2.0;
System.out.println(averageC);
}
}</source>
7.5
Floating-Point Data Types: memory and length
Type float and type double are two primitive floating-point types in Java.
Data TypeDescriptionMemoryfloat-3.4E38 to +3.4E384 bytes in memorydouble-1.7E308 to +1.7E3088 bytes in memory
Examples of float literals include the following:
<source lang="java">
2elf 8.f .5f 0f 3.14f 9.0001e+12f</source>
Using ++ and -- with floating-point variables
<source lang="java">
public class MainClass{
public static void main(String[] arg){
double a = 12.12;
System.out.println( a-- );
System.out.println( a++ );
System.out.println( --a );
System.out.println( ++a );
}
}</source>
12.12 11.12 11.12 12.12
Write Floating-Point Literals with an exponent
Write the number as a decimal value followed by an E, or an e.
- Floating-point literals are of type double by default.
- To specify a value of type float, you append an f, or an F.
<source lang="java">
public class MainClass{
public static void main(String[] arg){
double f1 = 1.496E8;
double f2 = 9.0E-28;
System.out.println(f1);
System.out.println(f2);
System.out.println(f2 + f1);
}
}</source>
1.496E8 9.0E-28 1.496E8
