```
"3hello".replace("3(\\w+)".toRegex(), "$1hi")
...
# getting-startedp
poohbar
12/07/2017, 8:38 PM Copy code
"3hello".replace("3(\\w+)".toRegex(), "$1hi") Copy code
"hellohi"poohbar
12/07/2017, 8:38 PM"3hello".replace("3(\\w+)".toRegex(), "$1hi")"hellohi"