Java substring

https://docs.oracle.com/javase/7/docs/api/java/lang/String.html

• substring

  public String substring(int beginIndex,
                 int endIndex)

  Returns a new string that is a substring of this string. The substring begins at the specified beginIndex and extends to the character at index endIndex - 1. Thus the length of the substring is endIndex-beginIndex.

  Examples:

   "hamburger".substring(4, 8) returns "urge"
   "smiles".substring(1, 5) returns "mile"
   

  Parameters:

  beginIndex - the beginning index, inclusive.

  endIndex - the ending index, exclusive.

  Returns:

  the specified substring.

  Throws:

  IndexOutOfBoundsException - if the beginIndex is negative, or endIndex is larger than the length of this String object, or beginIndex is larger than endIndex.

   

   

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• 另外，java中，允许数组size为0，这样为了更方便统一进行处理。http://stackoverflow.com/questions/4612471/why-does-java-allow-arrays-of-size-0