[JAVA] String, StringBuffer, StringTokenizer 클래스

*스트링 객체는 수정 불가능

public class StringEx {
	public static void main(String[] args) {
		String str1 = "abcd";
		String str2 = new String("abcd");
		char[] data = {'a', 'b', 'c', 'd'};
		String str3 = new String(data);
		
		System.out.println(str1);
		System.out.println(str2);
		System.out.println(str3);
		
		System.out.println(str1.concat("efgh"));	//1회성
		str1 = str1.concat("efgh");	//계속 이어지게 하려면				
		System.out.println(str1);
	}
}

 

StringBuffer 문자열 바꾸는 방법

public class StringEx {
	public static void main(String[] args) {
		String str1 = "ab cd";
		String str2 = new String("a,b,c,d");
		char[] data = {'a', 'b', 'c', 'd'};
		String str3 = new String(data);
		StringBuffer sb = new StringBuffer("Java ");
		System.out.println(sb);
		sb.append("Program");
		System.out.println(sb);
		sb.insert(4, "**");
		System.out.println(sb);
	}
}

 

StringTokenizer

import java.util.StringTokenizer;

public class StringTokenizerEx {
	public static void main(String[] args) {
		String str = "Python,Java,Network,Database";
		StringTokenizer st = new StringTokenizer(str, ",");
		while(st.hasMoreTokens()) {
			System.out.println(st.nextToken());
		}
		
	}
}

결과