Why doesn't For loop iterate without compound assignment operators : Sorry for noob question, I am trying to replace every character of source string with "🥃". If I remove += from my code For loop iterates only once, can't seem to follow logic behind this?

However, if I use '+=' For loop iterates. Shouldn't iterations have equalled number of characters in String? I mean my understanding always was "For every “item” in “items”, execute this code."

```
let stringExample = "Hello, Playground"
var emptyString = ""

for _ in stringExample {
    
  emptyString = "🥃"
}
print(emptyString)

```

🥃