testprimitive.java

java的一个代码

public class TestPrimitive {
  public static void main(String[] args) {
    Integer i = new Integer(100);
    Double d = new Double("123.456");
    int j = i.intValue()+d.intValue();
    float f = i.floatValue()+d.floatValue();
    System.out.println(j);  System.out.println(f);
    double pi = Double.parseDouble("3.1415926");
    double r = Double.valueOf("2.0").doubleValue();
    double s = pi*r*r;
    System.out.println(s);
    try {
         int k = Integer.parseInt("1.25");
    } catch (NumberFormatException e) {
        System.out.println("数据格式不对!");
    }
    System.out.println(Integer.toBinaryString(123)+"B");
    System.out.println(Integer.toHexString(123)+"H");
    System.out.println(Integer.toOctalString(123)+"O");
  }
}