question: public static String leftPad ( String s , int minLength , char filling ) { int ln = s . length ( ) ; if ( minLength <= ln ) { return s ; } StringBuilder res = new StringBuilder ( minLength ) ; int dif = minLength - ln ; for ( int i = 0 ; i < dif ; i ++ ) { res . append ( filling ) ; } res . append ( s ) ; return res . toString ( ) ; }
target:  Pads the string at the left with the specified character until it reaches the desired length. If the string is longer than this length, then it returns the unchanged string.