java例程练习（String类的一些常用方法）

//String类常用方法集锦 
 
 [java]
 
 public class TestString { 
 
     public static void main(String[] args) { 
 
         String s1 = "sun java"; 
 
         String s2 = "Sun Java"; 
 
         //取字符 
 
         System.out.println(s1.charAt(1));//u 
 
         //长度 
 
         System.out.println(s2.length());//8 
 
         //子串位置 
 
         System.out.println(s1.indexOf("java"));//4 
 
         System.out.println(s1.indexOf("Java"));//-1 
 
         //与什么相等 
 
         System.out.println(s1.equals(s2));//false 
 
         System.out.println(s1.equalsIgnoreCase(s2));//true 
 
         //字符替换 
 
         String s = "我是程序员，我在学java"; 
 
         String sr = s.replace('我', '你'); 
 
         System.out.println(sr);//你是程序员，你在学java 
 
          
 
         //以什么字符串开头或结尾 
 
         String ss = "Welcome to Java World!"; 
 
         System.out.println(ss.startsWith("Welcome"));//true 
 
         System.out.println(ss.endsWith("World"));//false 
 
          
 
         //转成大写或小写 
 
         String ssL = ss.toLowerCase(); 
 
         String ssU = ss.toUpperCase(); 
 
         System.out.println(ssL);//welcome to java world! 
 
         System.out.println(ssU);//WELCOME TO JAVA WORLD! 
 





          
 
         //截子串 
 www.2cto.com  
 
         String subSS = ss.substring(11); 
 
         System.out.println(subSS);//
 Java World! 
 
          
 
         //去掉首位空格 
 
         String st = "  sun java  "; 
 
         String sp = st.trim(); 
 
         System.out.println(sp);//sun java 
 
          
 
         //valueOf静态方法求数字位数 
 
         int j = 1234567; 
 
         String sNumber = String.valueOf(j); 
 
         System.out.println("j是" + sNumber.length() + "位数");//j是7位数 
 
          
 
         //分割字符 
 
         String bd = "Mary,F,1976"; 
 
         String [] bdSplit = bd.split(","); 
 
         for(int i = 0; i < bdSplit.length; i++) { 
 
             System.out.println(bdSplit[i]); 
 
         } 
 
 //      Mary 
 
 //      F 
 
 //      1976 
 
          
 
          
 
     } 
 
 } 
 
 
 
 
 
 摘自 Yours风之恋