search a 2 dimensional array in java

Question

How does one iterate through a two dimensional array search for [ ] [Name]?

When the Name is found the Index should be returned so that I can change the values in that array.

[Index] [Values].

Also, how does the syntax look for the storing to the array found? [ ] [index]. Loop through index and set a value. [0] [1] = blah.

Thanks

Answer 1

Sometimes it's easier and always cleaner to put the search in a separate method:

 private Point find2DIndex(Object[][] array, Object search) {

    if (search == null || array == null) return null;

    for (int rowIndex = 0; rowIndex < array.length; rowIndex++ ) {
       Object[] row = array[rowIndex];
       if (row != null) {
          for (int columnIndex = 0; columnIndex < row.length; columnIndex++) {
             if (search.equals(row[columnIndex])) {
                 return new Point(rowIndex, columnIndex);
             }
          }
       }
    }
    return null; // value not found in array
 }

This will return the first match only. If you need all, collect all points in a List and return that list at the end.

---

Usage:

private void doSomething() {
  String[][] array = {{"one", "1"},{"two","2"}, {"three","3"}};
  Point index = find2DIndex(array, "two");

  // change one value at index
  if (index != null)
     array[index.x][index.y] = "TWO";

  // change everything in the whole row
  if (index != null) {
     String[] row = array[index.x];
     // change the values in that row
  }

}

Answer 2

Updated due to your comment:

for(String[] subarray : array){
   int foundIndex = -1;
   for(int i = 0; i < subarray.length; i++){
      if(subarray[i].equals(searchString)){
         foundIndex = i;
         break;
      }
   } 
   if(foundIndex != -1){
      // change all values that are not at position foundIndex
      for(int i = 0; i < subarray.length; i++){
         if(i != foundIndex){
            subarray[i] = "something";
         }
      } 
      break;
   }
}