public java.lang.StringBuilder append(char[] chars,int offset,int length){
  int newCount=count + length;
  if (newCount > value.length) {
    enlargeBuffer(newCount);
  }
  System.arraycopy(chars,offset,value,count,length);
  count=newCount;
  return this;
}

public java . lang . StringBuilder append ( char [ ] chars , int offset , int length ) { int newCount = count + length ; if ( newCount > value . length ) { enlargeBuffer ( newCount ) ; } System . arraycopy ( chars , offset , value , count , length ) ; count = newCount ; return this ; }
appends the string representation of a subarray of the char array argument to this string buffer . characters of the character array str , starting at index offset , are appended , in order , to the contents of this string buffer . the length of this string buffer increases by the value of len . the overall effect is exactly as if the arguments were converted to a string by the method string . valueof ( char [ ] , int , int ) and the characters of that string were then appended to this stringbuffer object .
