指派
指派:是給變量指定一個值或者是改變一個變量的值。
int time = 60;
variable = expression;//變量類型 變量名 = 表達式
public class TestJava {
public static void main(String[] args){
//聲明變量
int speed,salary;
float time,basicSalary,prize,distance;
char alphabet;
//給變量指派
speed = ;
alphabet = 'a';
time = ;
basicSalary = f;
prize = f;
//通過表達式給變量指派
salary = (int)(basicSalary+prize);
distance = speed *time;
System.out.println(alphabet);
System.out.println(salary);
System.out.println(distance);
}
}
初始化
局部變量:必須顯示進行初始化。
執行個體變量和類變量:編譯器可以自動對他們進行初始化。
boolean:false
char:’\000’
byte:0(byte) 00000000
short:0(byte)0000000000000000
int:0
long:0L
float:0.0F
double:0.0D
public class TestJava {
//聲明類變量
static boolean aBoolean;
static char achar;//'\000'
static byte abyte;
static short ashort;
static int aint;
static long along;
static float afloat;
static double adouble;
public static void main(String[] args){
System.out.println("aBoolean="+aBoolean);
System.out.println("achar="+achar);
System.out.println("abyte="+abyte);
System.out.println("ashort="+ashort);
System.out.println("aint="+aint);
System.out.println("along="+along);
System.out.println("afloat="+afloat);
System.out.println("adouble="+adouble);
}
}