String.equals() with multiple conditions (and one action on result)

Question

Is it possible to do something like this in Java for Android (this is a pseudo code)

IF (some_string.equals("john" OR "mary" OR "peter" OR "etc."){
   THEN do something
}

?

At the moment this is done via multiple String.equals() condition with || among them.

Answer 1

Possibilities:

• Use String.equals():

  if (some_string.equals("john") ||
      some_string.equals("mary") ||
      some_string.equals("peter"))
  {
  }
  

• Use a regular expression:

  if (some_string.matches("john|mary|peter"))
  {
  }
  

• Store a list of strings to be matched against in a Collection and search the collection:

  Set<String> names = new HashSet<String>();
  names.add("john");
  names.add("mary");
  names.add("peter");
  
  if (names.contains(some_string))
  {
  }
  

Answer 2

if (Arrays.asList("John", "Mary", "Peter").contains(name)) {
}

• This is not as fast as using a prepared Set, but it performs no worse than using OR.
• This doesn't crash when name is NULL (same with Set).
• I like it because it looks clean

Answer 3

Keep the acceptable values in a HashSet and check if your string exists using the contains method:

Set<String> accept = new HashSet<String>(Arrays.asList(new String[] {"john", "mary", "peter"}));
if (accept.contains(some_string)) {
    //...
}

Answer 4

Your current implementation is correct. The suggested is not possible but the pseudo code would be implemented with multiple equal() calls and ||.

Answer 5

If you develop for Android KitKat or newer, you could also use a switch statement (see: Android coding with switch (String)). e.g.

switch(yourString)
{
     case "john":
          //do something for john
     case "mary":
          //do something for mary
}

Answer 6

No,its check like if string is "john" OR "mary" OR "peter" OR "etc."

you should check using ||

Like.,,if(str.equals("john") || str.equals("mary") || str.equals("peter"))

Answer 7

Pattern p = Pattern.compile("tom"); //the regular-expression pattern
Matcher m = p.matcher("(bob)(tom)(harry)"); //The data to find matches with

while (m.find()) {
    //do something???
}   

Use regex to find a match maybe?

Or create an array

 String[] a = new String[]{
        "tom",
        "bob",
        "harry"
 };

 if(a.contains(stringtomatch)){
     //do something
 }