1.2 StringBuilder類的常用方法 A:構造方法: StringBuilder() B:成員方法: public int capacity():返回當前容量 (理論值) public int length():返回長度(已經存儲的字符個數) public StringBuilder append(任意類型):添加數據，并返回自身對象 public StringBuilder reverse():反轉功能 1.2.1 案例代碼十三:
package com.itheima_01;
/** StringBuilder:是一個可變的字符串。字符串緩沖區類。** String和StringBuilder的區別：* String的內容是固定的。* StringBuilder的內容是可變的。** 構造方法：* StringBuilder()** 成員方法：* public int capacity():返回當前容量* public int length():返回長度（字符數）** 容量：理論值* 長度：實際值*/
public class StringBuilderDemo {
public static void main(String[] args) {
//創建對象
StringBuilder sb = new StringBuilder();
System.out.println("sb:"+sb);
System.out.println("sb.capacity():"+sb.capacity());
System.out.println("sb.length():"+sb.length());
}
}
1.2.2 案例代碼十四:
package com.itheima_02;
/** 添加功能* public StringBuilder append(任意類型):添加數據，并返回自身對象* 反轉功能* public StringBuilder reverse()*/
public class StringBuilderDemo {
public static void main(String[] args) {
//創建對象
StringBuilder sb = new StringBuilder();
//public StringBuilder append(任意類型)
//StringBuilder sb2 = sb.append("hello");
/*
System.out.println("sb:"+sb);
System.out.println("sb2:"+sb2);
System.out.println(sb == sb2); //true
*/
/*
sb.append("hello");
sb.append("world");
sb.append(true);
sb.append(100);
*/
//鏈式編程
sb.append("hello").append("world").append(true).append(100);
System.out.println("sb:"+sb);
//public StringBuilder reverse()
sb.reverse();
System.out.println("sb:"+sb);
}
}
