stringer.java

java课程的资料以及实验的代码

// Stringer.java

public class Stringer {
  public static void main(String[] args) {
        String day= new String("Monday");
        String str1 = "ABCD";
        String str2 = "ABCDE";
        String str3 = new String("ABCD");

        //str1[0]= 'a';   // 字符串不等于字符数组！
        
        StringBuffer aday=new StringBuffer("Monday");
        String bday = day.toUpperCase();
        aday.append(" Wednesday");
        aday.insert(6," Tuesday");
        
        System.out.println("day="+day+"\nbday="+bday+"\naday="+aday.toString());
        System.out.println(str1==str2);
        System.out.println(str1==str3);
        System.out.println(str1.equals(str3));  // 字符串的比较

        String str4= "   This is a line  ";
        // 字符串对象的所有操作不会改变原来的对象
        System.out.println(str4.trim());
        System.out.println("\""+str4+"\"");

		// 通过字符数组构造字符串
        char[] charr={ 'G', 'o', 'o', 'd' };
        String str5=new String(charr);
        System.out.println(str5);
        
        // 字符串操作
        String str6 = "Java Language";
        System.out.println(str6);
        int i=str6.length();
        System.out.println("Length="+i);
        i = str6.indexOf('a');
        System.out.println("index Of a="+i);
        i = str6.lastIndexOf('a');
        System.out.println("Last Index Of a="+i);
        i = str6.indexOf("ang");
        System.out.println("Index Of ang="+i);
        System.out.println("substring(5,9)="+str6.substring(5,9));
        System.out.println("replace="+str6.replace('a','e'));
  }
}