Can anyone please explain what is java string replace all ? What is function? Where and how we use this?

Question

Java

Answer 1

ie. it changes all "x" substrings to "*"
String str = "2x2x2";
String result = str.replaceAll( "x", "*");
System.out.println( result ); //2*2*2

meaning of term function depends on the context
generally it changes something to something other