java常用字符串处理

/*
* java.lang.String类中常见的方法：（字符串处理常用的方法）
* 1.参数不严格 ;    2,字符串支持正则表达式
* 
* 1、length():
*     制定一个字符串的长度；
*    
* 2、substring(int begin)
*    substring(int beginindex, int endindex)
*     substring()，参数从零开始数字符串；
*     
* 3、split(String s1)
*    split(String s2, int i)
* 
* 4、startsWith(String s1)
*    startsWith(String s2, int i)
*    endsWith(String s3)
* 
* 5、replace(String sb, String st)
*    replaceAll(String sb, String st)
* 
*/

public class TestString {

    public static void main(String[] args){
   new TestString().testLength();
   new TestString().testSubstring();
   new TestString().testSplit();
   new TestString().testStartsendsWith();
   new TestString().testReplaceAll();
}


    // 1、length():
    public void testLength(){
    String slen = "abc";
    String slenn = new String("abcdefg");
    int i = slen.length();
    int k = slenn.length();
    System.out.println(i);
    System.out.println(k);
    System.out.println("-----------------------------");
    }


    // 2、substring(int begin)、substring(int beginindex, int endindex)
    // 注意：字符串从零开始数
    public void testSubstring(){
    String se = new String("abcdefgh");
    String sea = se.substring(3);
    String seaa = se.substring(3,5);
    System.out.println(sea);
    System.out.println(seaa);
    System.out.println("--------------------------------");
    }


    // 3、split(String s1)、split(String s2, int i)
    public void testSplit(){
         String s = "阳光:沙滩:海浪:仙人掌";
         String[] results = s.split(":");
         String[] result = s.split(":",3);
         for(String each:results){
            System.out.println(each);
         }
         System.out.println("------");
         for(String each:result){
          System.out.println(each);
         }
         System.out.println("-----------------------------------");
     }


    // 4、startsWith(String s1)、startsWith(String s2, int i)、endsWith(String s3)
    public void testStartsendsWith(){
    String str2 = new String("zyxwvuabcdef");
    boolean bstart = str2.startsWith("z");
    boolean bend = str2.endsWith("f");
    if(bstart){
       System.out.println("true");
    }else{
       System.out.println("false");
    }
    if(bend){
       System.out.println("true");
    }else{
       System.out.println("false");
    }
    System.out.println("---------------------------------------");
    }


    // 5、replace(String sb, String st)、replaceAll(String sb, String st)
    public void testReplaceAll(){
    String sre = new String("cbadzyc");
    String rsre = sre.replace("c","a");
    String rasre = sre.replaceAll("c","b");
    System.out.println(rsre);
    System.out.println(rasre);
    System.out.println("-----------------------------------------");
    }
}