14일차 StringBuilder

package com.test;

public class StringBuilderStudy {

	public static void main(String[] args) {
		
		//StringBuilder sb = new StringBuilder();
		StringBuffer sb = new StringBuffer();//버퍼 크기를 지정할 수있음.
		
		//좋은 예
		sb.append("1번"); 
		sb.append("2번");
		sb.append(3);
		sb.append(4.555f);//float 실수형
		sb.append(5.666666);//double 실수형
		
		//나쁜 예
		String name="1번"+"2번"+3+4.555f+5.666666;
		
		System.out.println(sb);			   //(x)
		System.out.println(sb.toString()); //일반적
	
		System.out.println("length = "+sb.length());
		
		sb.insert(5, "++++++");
		System.out.println(sb.toString());//일반적
		
		sb.delete(0, 2);
		System.out.println(sb.toString());
		
		System.out.println(sb.deleteCharAt(0));
		
		System.out.println(sb.replace(0, 2, "******"));
		System.out.println(sb.reverse());
	}

} 

1번2번34.5555.666666

1번2번34.5555.666666

length = 18

1번2번3++++++4.5555.666666

2번3++++++4.5555.666666

번3++++++4.5555.666666

******++++++4.5555.666666

666666.5555.4++++++******