Question: ```
void replace3sWith4s(int[] replace){
  for (int i = 0;i<replace.length;i++){
      if (replace[i]==3);{
          replace[i]=4;
      }
  }
}

```

My program is replacing all numbers with #4 but I want to have an array that contains 3,
takes an integer array, and changes any element that has the value 3 to instead have the value 4.

Answer: 
```
(replace[i]==3); 

```

Is like writing 

```
(replace[i]==3) { }

```

Which does nothing.

Your code is equivalent to this code:

```
void replace3sWith4s(int[] replace){
  for (int i = 0;i<replace.length;i++){
      if (replace[i]==3) { }
      replace[i]=4;  //Always reachable
      }
  }
}

```

To fix your code, remove the semicolon:

```
(replace[i]==3); 
               ^

```
also You can try this method at if statement according to your array type 

```
if (replace[i].equals("3")){

replace[i]=4;   

```

}