基本数据类型由该语言预先定义，并由Java中的关键字命名。这是显示原始数据类型的默认值的示例。
public class Demo {
static boolean val1;
static double val2;
static float val3;
static int val4;
static long val5;
static String val6;
public static void main(String[] args) {
System.out.println("Default values.....");
System.out.println("Val1 = " + val1);
System.out.println("Val2 = " + val2);
System.out.println("Val3 = " + val3);
System.out.println("Val4 = " + val4);
System.out.println("Val5 = " + val5);
System.out.println("Val6 = " + val6);
}
}输出结果
Default values..... Val1 = false Val2 = 0.0 Val3 = 0.0 Val4 = 0 Val5 = 0 Val6 = null
上面，我们首先声明了特定类型的变量。请记住，要获取默认值，您无需为变量分配值。
static boolean val1; static double val2; static float val3; static int val4; static long val5; static String val6;
现在要显示默认值，您只需要打印变量。
System.out.println("Val1 = " + val1);
System.out.println("Val2 = " + val2);
System.out.println("Val3 = " + val3);
System.out.println("Val4 = " + val4);
System.out.println("Val5 = " + val5);
System.out.println("Val6 = " + val6);