17

第七题:
找出下列代码中出错的地方,并将其改正.
public class Test01 {
public static void main(String[] args) {
int a; //int a = 0;
System.out.println(a); //a没有没赋值直接使用
{
int c = 20;
System.out.println(c);
}
c = 30; //c取不到值 int c = 30;
System.out.println(c); //c取不到值
}
}

public class Test02 {
public static void main(String[] args) {
byte b = 3;
b = b + 4; //b需要强转 b = (byte)(b+4); b+=4;
System.out.println("b=" + b);
}
}
public class Test07 {
public static void main(String[] args) {
int x = 2;
{
int y = 6;
System.out.println("x is " + x);
System.out.println("y is " + y);
}
y = x; //y取不到值 int y = x;
System.out.println("x is " + x);
}
}