逻辑运算符
package operator;
//逻辑运算符
public class Demo05 {
public static void main(String[] args) {
// 与 (and) 或 (or) 非 (取反)
boolean a = true;
boolean b = false;
System.out.println("a && b:"+(a&&b));//逻辑与运算:两个变量都为真,结果才为true
System.out.println("a || b:"+(a||b));//逻辑或运算:两个变量又一个为真,则结果才为true
System.out.println("!(a && b):"+!(a&&b));//如果为真,则变为假,如果是假则变为真
//短路运算
int c =5;
boolean d = (c<4)&&(c++<4);
System.out.println(d);
System.out.println(c);
}
}
位运算
package operator;
import java.util.Scanner;
public class Demo06 {
public static void main(String[] args) {
/*位运算
A = 0011 1100
B = 0000 1101
--------------------------------
A&B = 0000 1100 有0为0无0为1
A|B = 0011 1101 有1为1无1为0
A^B = 0011 0001 相同为0反之为1
~B = 1111 0010 取反
2*8 = 16 2*2*2*2
效率极高!!!
<< *2
>> /2
0000 0000 0
0000 0001 1
0000 0010 2
0000 0011 3
0000 0100 4
0000 1000 8
0001 0000
*/
System.out.println(2<<3);
}
}
package operator;
public class Demo07 {
public static void main(String[] args) {
int a = 10;
int b = 20;
a+=b;//a = a+b
a-=b;//a = a-b
System.out.println(a);
//字符串连接符 + ,String
System.out.println(a+b);//30
System.out.println(""+a+b);//1020
System.out.println(a+b+"");//30
}
}
三元运算符
package operator;
//三元运算符
public class Demo08 {
public static void main(String[] args) {
// x ? y : z
//如果x==true , 则结果为y,否则结果为z
int score = 50;
String type = score <60 ?"不及格":"及格";//必须掌握
// if
System.out.println(type);
}
}