Question

I’m trying to write a method that takes an input string, and adds a character to it at a specified position. The inputString is 42 characters long, and is divided into 7 “columns”, when the input is given by the user, the method should take that input and place an “X” into the appropriate position. Here is the code:

private String enterToken(String tokenSymbol, String inputString, int column){
   String columnEdit = inputString.substring(column*6-6,column*6); 

   String columnEdit1 = columnEdit.trim();
   String columnEdit2 = columnEdit1+tokenSymbol+"                 ";
   String columnEdit3 = columnEdit2.substring(0,6);
   String start = inputString.replace(inputString.substring(column*6-6,column*6),columnEdit3);
   System.out.println(start);
   return start;

 }

When I give it an input of 42 spaces and I give it a column 2, for example, it gives me an output of

"X     X     X     X     X     X     X     "

whereas it SHOULD give me one like

"      X                                   " 

Any ideas?

Answer 1

Here is a solution :

private String enterToken(String tokenSymbol, String inputString, int column) {
    int colWidth = inputString.length() / 7;
    int tokenPos = (column-1) * colWidth;
    String inputStart = inputString.substring(0, tokenPos);
    String inputEnd = inputString.substring(tokenPos+1);
    return inputStart + tokenSymbol+inputEnd;
}