Compare one String with multiple values in one expression

Question

I have one String variable  str with possible values  val1  val2 and val3   I want to compare  with equal case  str to all of these values using an if statement  for example   if  val1  equalsIgnoreCase str    val2  equalsIgnoreCase str    val3 equalsIgnoreCase str             remaining code     Is there a way to avoid using multiple OR      operators and compare values in one expression  For example  like this    if   val1  OR  val2  OR  val3   equalsIgnoreCase str      this is only an idea

User · Answer

The are many solutions suggested and most are working solutions. However i must add here that people suggesting using regex i.e str.matches("val1|val2|val3") is okay however

it's not performant if the method/code is called many times
it's not null safe

I would suggest to use apache commons lang3 stringUtils StringUtils.equalsAny(str, "val1", "val2", "val3") instead

Test:

public static void main(String[] args) {
        String var = "val1";
        long t, t1 = 0, t2 = 0;

        for (int i = 0; i < 1000; i++) {
            t = System.currentTimeMillis();
            var.matches("val1|val2|val3");
            t1 += System.currentTimeMillis() - t;

            t = System.currentTimeMillis();
            StringUtils.equalsAny(var, "val1", "val2", "val3");
            t2 += System.currentTimeMillis() - t;
        }
        System.out.println("Matches took + " + t1 + " ms\nStringUtils took " + t2 + " ms");
    }

Results after 1000 iteration:

Matches took + 18 ms
StringUtils took 7 ms

User · Answer

Starting from Java 9  you can use either of following  List of  val1    val2    val3   contains str toLowerCase     Set of  val1    val2    val3   contains str toLowerCase

User · Answer

Here a performance test with multiples alternatives  some are case sensitive and others case insensitive    public static void main String   args           Why 4   4         The test contains 3 values  val1  val2 and val3   Checking 4 combinations will check the match on all values  and the non match         Try 4 times  lowercase  UPPERCASE  prefix   lowercase  prefix   UPPERCASE      final int NUMBER OF TESTS   4   4      final int EXCUTIONS BY TEST   1 000 000      int numberOfMatches      int numberOfExpectedCaseSensitiveMatches      int numberOfExpectedCaseInsensitiveMatches         Start at -1  because the first execution is always slower  and should be ignored      for  int i   -1  i  lt  NUMBER OF TESTS  i              int iInsensitive   i   4          List lt String gt  testType   new ArrayList lt  gt             List lt Long gt  timeSteps   new ArrayList lt  gt             String name    i   4  gt  1    dummyPrefix            i   4    2    0    val     VAL    iInsensitive           numberOfExpectedCaseSensitiveMatches   1  lt   i  amp  amp  i  lt   3   EXCUTIONS BY TEST   0          numberOfExpectedCaseInsensitiveMatches   1  lt   iInsensitive  amp  amp  iInsensitive  lt   3  amp  amp  i   4  lt   1   EXCUTIONS BY TEST   0          timeSteps add System currentTimeMillis               -----------------------------------------         numberOfMatches   0          testType add  List  Case sensitive             for  int j   0  j  lt  EXCUTIONS BY TEST  j                  if  Arrays asList  val1    val2    val3   contains name                     numberOfMatches                                    if  numberOfMatches    numberOfExpectedCaseSensitiveMatches                throw new RuntimeException                      timeSteps add System currentTimeMillis                -----------------------------------------         numberOfMatches   0          testType add  Set  Case sensitive             for  int j   0  j  lt  EXCUTIONS BY TEST  j                  if  new HashSet lt  gt  Arrays asList new String     val1    val2    val3     contains name                     numberOfMatches                                    if  numberOfMatches    numberOfExpectedCaseSensitiveMatches                throw new RuntimeException                      timeSteps add System currentTimeMillis                -----------------------------------------         numberOfMatches   0          testType add  OR  Case sensitive             for  int j   0  j  lt  EXCUTIONS BY TEST  j                  if   val1  equals name      val2  equals name      val3  equals name                     numberOfMatches                                    if  numberOfMatches    numberOfExpectedCaseSensitiveMatches                throw new RuntimeException                      timeSteps add System currentTimeMillis                -----------------------------------------         numberOfMatches   0          testType add  OR  Case insensitive             for  int j   0  j  lt  EXCUTIONS BY TEST  j                  if   val1  equalsIgnoreCase name      val2  equalsIgnoreCase name      val3  equalsIgnoreCase name                     numberOfMatches                                    if  numberOfMatches    numberOfExpectedCaseInsensitiveMatches                throw new RuntimeException                      timeSteps add System currentTimeMillis                -----------------------------------------         numberOfMatches   0          testType add  ArraysBinarySearch Case sensitive             for  int j   0  j  lt  EXCUTIONS BY TEST  j                  if  Arrays binarySearch new String    val1    val2    val3    name   gt   0                    numberOfMatches                                    if  numberOfMatches    numberOfExpectedCaseSensitiveMatches                throw new RuntimeException                      timeSteps add System currentTimeMillis                -----------------------------------------         numberOfMatches   0          testType add  Java8 Stream  Case sensitive             for  int j   0  j  lt  EXCUTIONS BY TEST  j                  if  Stream of  val1    val2    val3   anyMatch name  equals                     numberOfMatches                                    if  numberOfMatches    numberOfExpectedCaseSensitiveMatches                throw new RuntimeException                      timeSteps add System currentTimeMillis                -----------------------------------------         numberOfMatches   0          testType add  Java8 Stream  Case insensitive             for  int j   0  j  lt  EXCUTIONS BY TEST  j                  if  Stream of  val1    val2    val3   anyMatch name  equalsIgnoreCase                     numberOfMatches                                    if  numberOfMatches    numberOfExpectedCaseInsensitiveMatches                throw new RuntimeException                      timeSteps add System currentTimeMillis                -----------------------------------------         numberOfMatches   0          testType add  RegEx  Case sensitive                WARNING  if values contains special characters  that should be escaped by Pattern quote String          for  int j   0  j  lt  EXCUTIONS BY TEST  j                  if  name matches  val1 val2 val3                      numberOfMatches                                    if  numberOfMatches    numberOfExpectedCaseSensitiveMatches                throw new RuntimeException                      timeSteps add System currentTimeMillis                -----------------------------------------         numberOfMatches   0          testType add  RegEx  Case insensitive                WARNING  if values contains special characters  that should be escaped by Pattern quote String          for  int j   0  j  lt  EXCUTIONS BY TEST  j                  if  name matches    i val1 val2 val3                      numberOfMatches                                    if  numberOfMatches    numberOfExpectedCaseInsensitiveMatches                throw new RuntimeException                      timeSteps add System currentTimeMillis                -----------------------------------------         numberOfMatches   0          testType add  StringIndexOf  Case sensitive                WARNING  the string to be matched should not contains the SEPARATOR          final String SEPARATOR                for  int j   0  j  lt  EXCUTIONS BY TEST  j                     Don t forget the SEPARATOR at the begin and at the end              if   SEPARATOR  val1  SEPARATOR  val2  SEPARATOR  val3  SEPARATOR  indexOf SEPARATOR   name   SEPARATOR  gt  0                    numberOfMatches                                    if  numberOfMatches    numberOfExpectedCaseSensitiveMatches                throw new RuntimeException                      timeSteps add System currentTimeMillis                -----------------------------------------         StringBuffer sb   new StringBuffer  Test    append i                   append    name      append name                   append    numberOfExpectedCaseSensitiveMatches      append numberOfExpectedCaseSensitiveMatches                   append    numberOfExpectedCaseInsensitiveMatches      append numberOfExpectedCaseInsensitiveMatches                   append      n            for  int j   0  j  lt  testType size    j                  sb append String format       4d ms with  s n   timeSteps get j   1 -timeSteps get j   testType get j                       System out println sb toString               Output  only the worse case  that is when have to check all elements without match none    Test 4  name   VAL0  numberOfExpectedCaseSensitiveMatches   0  numberOfExpectedCaseInsensitiveMatches   0      43 ms with List  Case sensitive   378 ms with Set  Case sensitive    22 ms with OR  Case sensitive   254 ms with OR  Case insensitive    35 ms with ArraysBinarySearch Case sensitive   266 ms with Java8 Stream  Case sensitive   531 ms with Java8 Stream  Case insensitive  1009 ms with RegEx  Case sensitive  1201 ms with RegEx  Case insensitive   107 ms with StringIndexOf  Case sensitive

User · Answer

Remember in Java a quoted String is still a String object  Therefore you can use the String function contains   to test for a range of Strings or integers using this method   if   A C Viking G M Ocelot  contains mAnswer           for numbers it s a tad more involved but still works   if   1 4 5 9 10 17 23 96457  contains String valueOf mNumAnswer

User · Answer

For those who came here for exact equality checks  not ignoring case   I find that if  Arrays asList str1  str2  str3  contains strToCheck                is one of  if the most concise solution  and is available on Java 7

User · Answer

ArrayUtils may be helpful   ArrayUtils contains new String    1    2     1

User · Answer

string matches  a b c d      works fine for me

User · Answer

Apache Commons Collection class   StringUtils equalsAny CharSequence string  CharSequence    searchStrings   So in your case  it would be  StringUtils equalsAny str   val1    val2    val3

User · Answer

Sorry for reponening this old question  for Java 8  I think the best solution is the one provided by Elliott Frisch  Stream of  str1    str2    str3   anyMatches str  equalsIgnoreCase   but it seems like it s missing one of the simplest solution for eldest version of Java   if Arrays asList  val1    val2    val3         val n   contains str toLowerCase              You could apply some error prevenction by checking the non-nullity of variable str  and by caching the list once created  using ArrayList to speed up searches for long lists      List of lower-case possibilities List lt String gt  list   new ArrayList lt  gt  Arrays asList  val1    val2    val3         val n      if str    null  amp  amp  list contains str toLowerCase

User · Answer

In Java 8   you might use a Stream lt T gt  and anyMatch Predicate lt   super T gt   with something like  if  Stream of  val1    val2    val3   anyMatch str  equalsIgnoreCase

User · Answer

Since this question has been reopened anyway  I might just as well propose an enum solution   enum ValidValues      VAL1  VAL2  VAL3      public static boolean isValid String input           return Stream of ValidValues values                         map ValidValues  name                       anyMatch s - gt  s equalsIgnoreCase input             Or you can just use the stream statement with   Stream of  val1    val2    val3          anyMatch s - gt  s equalsIgnoreCase str     if you only use it in one place

User · Answer

You could store all the strings that you want to compare str with into a collection and check if the collection contains str  Store all strings in the collection as lowercase and convert str to lowercase before querying the collection  For example   Set lt String gt  strings   new HashSet lt String gt     strings add  val1    strings add  val2     String str    Val1    if  strings contains str toLowerCase

User · Answer

You can achieve this with Collections framework  Put all your options in a Collection say something like Collection lt String gt  options    Then loop throgh this to compare your string with the list elements and if it is you can return a boolean value true and otherwise false

User · Answer

Yet another alternative  kinda similar to https   stackoverflow com a 32241628 6095216 above  using StringUtils from the apache commons library  https   commons apache org proper commons-lang apidocs org apache commons lang3 StringUtils html equalsAnyIgnoreCase-java lang CharSequence-java lang CharSequence   -  if  StringUtils equalsAnyIgnoreCase str   val1    val2    val3           remaining code

User · Answer

Small enhancement to perfectly valid  hmjd s answer  you can use following syntax     class A      final Set lt String gt  strings   new HashSet lt  gt           add  val1        add  val2                       if  strings contains str toLowerCase                         It allows you to initialize you Set in-place

User · Answer

Just use var-args and write your own static method   public static boolean compareWithMany String first  String next  String     rest        if first equalsIgnoreCase next           return true      for int i   0  i  lt  rest length  i                  if first equalsIgnoreCase rest i                return true            return false     public static void main String   args        final String str    val1       System out println compareWithMany str   val1    val2    val3

User · Answer

I found the better solution  This can be achieved through RegEx    if  str matches  val1 val2 val3              remaining code     For case insensitive matching   if  str matches    i val1 val2 val3              remaining code

User · Answer

No  there is no such possibility  Allthough  one could imagine   public static boolean contains String s  Collection lt String gt c        for  String ss   c           if  s equalsIgnoreCase ss   return true            return false

[java] Compare one String with multiple values in one expression

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