Java 2 dimensional array of Strings error -

public class robotzoneclass implements robotzone {     string[][] map;      public robotzoneclass(int rows, int columns){         map= new string[rows][columns];     }      public void readmap(string map,int row) {         for(int i=0;i<map.length()-1;i++){             map[row][i]=map.charat(i);         }     } } 

i error: the type of expression must array type resolved string. why happening?

you shadowing global map variable:

in computer programming, variable shadowing occurs when variable declared within scope (decision block, method, or inner class) has same name variable declared in outer scope.

rename parameter readmap:

public void readmap(string othermap,int row) {     for(int i=0;i<map.length()-1;i++){         map[row][i]=othermap.charat(i);     } } 

also, seems you're using two-dimensional array of strings (which three-dimensional array of characters) map when want two-dimensional character array, array of strings.

try this:

public class robotzoneclass implements robotzone {     string[] map;      public robotzoneclass(int rows){         map = new string[rows];     }       public void readmap(string newrow, int row) {         // replaces row in map         map[row]=newrow;     }      // rest of implementation }