例一：

class DataDemo01{

public static void main(String[] args){

int num =999999999999999999999999;

}

}

例二：

class DataDemo02{

public static void main(String[] args){

int max =Integer.MAX_VALUE;

System.out.println("整型的最大值："+max);

System.out.println("整型最大值 +1："+(max+1));

System.out.println("整型最大值 +2："+(max+2));

}

}

例三：

public class DataDemo03{

public static void main(String[] args){

int max =Integer.MAX_VALUE;

System.out.println("整型的最大值："+max);

System.out.println("整型最大值 +1："+(max+1));

System.out.println("整型最大值 +2："+(max+2L));

System.out.println("整型最大值 +2："+((long)max+2));

}

}

例四：

public class DataDemo04{

public static void main(String[] args){

char ch1='a';

char ch2=97;

System.out.println("ch1 = "+ch1);

System.out.println("ch2 = "+ch2);

}

}

例五：

public class DataDemo05{

public static void main(String[] args){

char ch1='\"';

char ch2='\\';

System.out.println("ch1 = "+ch1);

System.out.println("ch2 = "+ch2);

System.out.println("\"Hello World\"");

}

}

例六：

public class DataDemo06{

public static void main(String[] args){

float num=3.0f;

System.out.println("两个小数相乘："+num*num);

}

}

例七：

public class DataDemo07{

public static void main(String[] args){

boolean flag=true;

System.out.println("flag = "+flag);

}

}