有些时候,需要由较短的字符串构建新的字符串,这时候可以用到StringBuilder类
package java20180708_1;
public class Test2018070803 {
public static void main(String[] args) {
// TODO Auto-generated method stub
StringBuilder stringBuilder = new StringBuilder();
//向其中添加内容,append()
//字符串
stringBuilder.append("a");
stringBuilder.append("b");
stringBuilder.append("c");
stringBuilder.append("d");
//添加char类型
stringBuilder.append('e');
//虽然可以直接输出,但是最好用 toString()方法
System.out.println(stringBuilder.toString());
//void setCharAt(int i,char c)
//将第i个代码单元设置为c
stringBuilder.setCharAt(0, 'z');
System.out.println(stringBuilder.toString());
//StringBuilder insert(int offset,String str)
//StringBuilder insert(int offset,char str)
//在offset处插入
stringBuilder.insert(5, "fg");
System.out.println(stringBuilder.toString());
stringBuilder.insert(7, 'h');
System.out.println(stringBuilder.toString());
//StringBuilder delete(int startIndex,int endIndex)
//删除start到end-1
stringBuilder.delete(0, 2);
System.out.println(stringBuilder.toString());
}
}
输出结果为:
abcde
zbcde
zbcdefg
zbcdefgh
cdefgh