Java String

• String
  • int capacity()
  • char charAt(int index)
  • int indexOf(String str)
  • int indexOf(String str, int fromIndex)
  • int lastIndexOf(String str)
  • int lastIndexOf(String str, int fromIndex)
  • int length()
  • String substring(int start)
  • String substring(int start, int end) output = input[start, end)
  • String toString()
  • boolean startsWith(String prefix)
  • boolean endsWith(String suffix)
  • int compareTo(String anotherString)
    • compares two strings lexicographically.
    • "abc" < "abcd"
    • "abc" < "abcd"
    • "abc" < "b"
  • String[] split(String regex)
  • String[] split(String regex, int limit)
    • "a/b/c/d" -> .split("/", 2)
  • String trim()
    • remove leading and trailing white spaces.
• StringBuilder
• StringBuffer - thread-safe / synchronized
  • same as String
  • StringBuffer append(String s)
  • StringBuffer reverse()
  • delete(int start, int end)
  • deleteCharAt(int index)
  • insert(int offset, int i)
  • replace(int start, int end, String str)

public class Test{
  public static void main(String args[]){
    StringBuffer sBuffer = new StringBuffer("菜鸟教程官网：");
    sBuffer.append("www");
    sBuffer.append(".runoob");
    sBuffer.append(".com");
    System.out.println(sBuffer);  
  }
}

String to Char Array & Char Array to String

• substring - [startIndex, endIndex)
• new String - [offset, offset + count)

public char[] convert(String input){
    return input.toCharArray();
}

public String substring(String input, int offset, int count){
    return new String(input, offset, count);
}


public String convert(char[] input, int startIndex, int endIndex){
    return input.substring(startIndex, endIndex);
}

// String definition