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

```

Remove the semicolon.
It should be

```
if (replace[i]==3) {
      replace[i]=4;
}

```

The semicolon changes the meaning to

```
if (replace[i]==3)
    ;//do nothing

// Separate New block
{
    replace[i]=4;
}

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

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

replace[i]=4;   

```

}