StringBuffer应用

1.

StringBuffer.substring(int start, int end)方法

.StringBuilder.substring(int start, int end) 方法返回一个新的String，它包含了目前这个序列中包含的字符序列。子字符串的start在指定的起始和延伸处的字符索引 end - 1.

实例：

下面的例子显示使用的java.lang.StringBuilder.substring()方法.

package com.yiibai;import java.lang.*;public class StringBuilderDemo {  public static void main(String[] args) {      StringBuilder str = new StringBuilder("admin");    System.out.println("string = " + str);    // prints substring from index 3    System.out.println("substring is = " + str.substring(3));    /* prints substring from index 1 to 4 excluding character    at 4th index */    System.out.println("substring is = " + str.substring(1, 4));  }}

让我们来编译和运行上面的程序，这将产生以下结果：

string = adminsubstring is = insubstring is = dmi

2..............................

StringBuffer.lastIndexOf()方法

StringBuilder.lastIndexOf(String str) 方法返回在此的最右边出现的指定子字符串的索引。

实例：

下面的例子说明了如何使用java.lang.StringBuilder.lastIndexOf()方法。

package com.yiibai;import java.lang.*;public class StringBuilderDemo {  public static void main(String[] args) {      StringBuilder str = new StringBuilder("tutorials point");    System.out.println("string = " + str);        /* returns the index within this string of the rightmost occurrence     of the specified substring */    System.out.println("last Index of a = " + str.lastIndexOf("a"));      // returns -1 as substring am is not found    System.out.println("last index of am = " + str.lastIndexOf("am"));  }}  

让我们来编译和运行上面的程序，这将产生以下结果：

string = tutorials pointlast Index of a = 6last index of am = -1