包装类和字符串

包装类和字符串

package test;

import java.util.StringTokenizer;

public class test02 {
    
    

	public static void main(String[] args) {
    
    
		
		Double db1= Double.valueOf(7.8);   //转成包装类
		
		float df= db1.floatValue();
		int dint=db1.intValue();
		short st=db1.shortValue();
		System.out.println(df*dint*st);
		

	 	String PI ="3.1415926";
	 	String s="12.345678";	 	
	 	System.out.println(s.indexOf(0));
	 	
	 	double r1=Double.valueOf(PI).doubleValue();
	 	System.out.println( "r1:"+r1);
	 	
	 	float pi=Float.parseFloat(PI);
	 	float f= Float.parseFloat(s);	 	
	 	double areas =  pi*f*f;	 	
	 	System.out.println(pi*f*f);
	 	System.out.println(areas);
	 	
	 	

	 
		StringTokenizer fl= new StringTokenizer("I|you love,like; 1234","|,; ");
		
		System.out.println( fl.nextToken());
		System.out.println( fl.nextToken());
		System.out.println( fl.nextToken());
		System.out.println( fl.nextToken());
		System.out.println( fl.nextToken());
		
		
		boolean c=Character.isDigit('a');
		System.out.println(c);
		System.out.println(Character.isLetter('A'));
		System.out.println(Character.isDigit('1'));
	 	
	 	
	}

}