算数运算符:+,-,*,/,%,++,--
package operator; public class Demo01 { public static void main(String[] args) { //二元运算符 //Ctrl = D :赋值当前行到下一行 int a = 10; int b = 20; int c = 25; int d = 25; int e = 35; System.out.println(a+b); System.out.println(c-b); System.out.println(a*e); System.out.println(d%b); System.out.println(d/(double)b); System.out.println(d/b);//精度不够 } }
package operator; public class Demo02 { public static void main(String[] args) { long a = 121313114123L; int b = 123; short c = 10; byte d = 8; System.out.println(a+b+c+d); //Long(包含long)高容量类型 System.out.println(b+c+d); //Int System.out.println(c+d); //Int System.out.println((double) c+d); //double(包含)高容量类型 } }
package operator; public class Demo04 { public static void main(String[] args) { // ++ -- 自增 自减 一元运算 int a =3; int b = a++; //执行完这行代码后,先给b赋值,再自增 //a++ a = a +1 System.out.println(a); // ++a a = a +1 int c = ++a; //执行完这行代码前,先自增,再给b赋值 System.out.println(a); System.out.println(b); System.out.println(c); //幂运算 2^3 2*2*2 = 8 很多运算,我们会使用一些工具类操作 double pow = Math.pow(3,2); System.out.println(pow); } }
赋值运算符:=
关系运算符:>,<,,>=, <=, ==, !=instanceof
package operator; public class Demo03 { public static void main(String[] args) { //关系运算符返回结果: 正确,错误 布尔值 int a = 10; int b = 20; int c = 21; System.out.println(a>b); System.out.println(a<b); System.out.println(a==c); System.out.println(b!=c); } }
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,全真为真 System.out.println("a || b: "+ (a||b));//逻辑或运算,全假为假 System.out.println("!(a && b): "+ !(a&&b));//真为假来假为真 //短路运算 int c = 5; boolean d = (c<4)&&(c++<4); System.out.println(c); System.out.println(d); boolean e = (c>4)||(c++<4); System.out.println(c); System.out.println(e); } }
位运算符:&,|,^,~,>>,<<,>>>
package operator; public class Demo06 { public static void main(String[] args) { /* A = 0011 1100 B = 0000 1101 ---------------------------- A&B = 0000 1100 A|B = 0011 1101 A^B = 0011 0001 ~B = 1111 0010 2*8 = 16 2*2*2*2 效率极高!!! << *2 >> /2 0 1 2 3 4 8 16 */ System.out.println(2<<3); } }
条件运算符:?,:
package operator; 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 = 80; String type = score < 60 ? "不及格":"及格"; //必须掌握 //if System.out.println(type); int score1 = 50; String type1 = score < 60 ? "不及格":"及格"; //必须掌握 //if System.out.println(type1); } }
扩展赋值运算符:+=,-=,*=,/=
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); System.out.println(a+b+""); } }