1 public static void main(String[] args) { 2 // Exams 1: 3 { 4 System.out.println("examples "+count++ +": "); 5 x--; 6 System.out.println(x); 7 myMethod(); 8 System.out.println(x+y+++x); 9 } 10 //Exams 2: 11 { 12 System.out.println("examples "+count++ +": "); 13 int j=0,temp=0; 14 for(int i=0;i<100;i++) 15 { 16 j=j++; 17 //java中间缓存变量机制 与以下等同 18 // temp=j; 19 // j=j+1; 20 // j=temp; 21 } 22 System.out.println(j); 23 } 24 //Exams 3: 25 System.out.println("examples "+count++ +": "); 26 { 27 int a=5,b=5; 28 if(!(a==b)&&(a==1+b++)) //前半段为false的话,后半段就不执行了 29 {} 30 System.out.println("a="+a+" b="+b); 31 } 32 //Exams 4: 33 { 34 System.out.println("examples "+count++ +": "); 35 char a='0'; 36 int b=a; 37 int l=3; 38 short s=1; 39 s+=1; 40 // a=a+1会报错,因为a+1为int转换,而 a为short,不能直接赋值给short 41 // a+=1是可以的 42 String bb=""; 43 assert(l==4):bb; 44 System.out.println(bb); 45 46 } 47 //Exams 5: 48 { 49 System.out.println("examples "+count++ +": "); 50 //注意到10.9 所以9也会进行转换变成9.0 51 int a=5; 52 System.out.println("value is "+((a<5)?10.9:9)); 53 } 54 //Exams 6: 55 { 56 System.out.println("examples "+count++ +": "); 57 58 //i是一个int类型的,所以x的int值为120,x被提升为int类型了 59 60 //java规范提到:当后两个表达式有一个是常量表达式(本题10),另一个类型是T, 61 //而常量表达式可以被T表示的时候,输出结果是T类型 62 char x='x'; 63 int i=10; 64 System.out.println(false?i:x); 65 System.out.println(false?10:x); 66 67 } 68 //Exams 7: 69 { 70 System.out.println("examples "+count++ +": "); 71 //移位运算的参数要先进行模的32运算,并且是对二进制的操作 72 Integer num=32; 73 System.out.println(num>>6); 74 75 System.out.println(Integer.toBinaryString(num>>32)); 76 } 77 78 //Exams 8: 79 { 80 System.out.println("examples "+count++ +": "); 81 82 try 83 { 84 System.out.println("to the try"); 85 int i=3/0; 86 //finally 依然执行的 87 //try中有return,finally会被执行且在return之前执行, 88 //因为return了之后函数会被销毁,所以是之前 89 return ; 90 } 91 catch(Exception e) 92 { 93 System.out.println("to the catch"); 94 } 95 finally 96 { 97 System.out.println("execute finally"); 98 } 99 }100 //Exams 9: 101 {102 System.out.println("examples "+count++ +": ");103 Testiplusplus x1=new Testiplusplus(1);104 changeValue(x1);105 System.out.println(x1.testNum);106 }107 //Exams 10: 108 109 {110 System.out.println("examples "+count++ +": ");111 // static int p; 编译会出错,局部变量,要放类内,算全局变量不赋初值才行112 System.out.println(p);113 }114 115 //Exams 11: 116 117 {118 System.out.println("examples "+count++ +": ");119 120 }121 }