How to compare Boolean

Question

Take this for example  excerpt from Java regex checker not working    while  checker        matcher   pattern matcher number       if matcher find            checker   true      else         year        Would it matter if  equals false  was used to check for the value of the Boolean checker   I know that there is this which is rather similar  However  obviously the question deals with primitive boolean and not the object wrapper  Boolean  thus   equals   would not be applicable   Also  should Boolean be dealt differently than boolean

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Using direct conditions  like          condition  will have a slight performance improvement over the  equals condition  as in one case you are calling the method from an object whereas direct comparisons are performed directly

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As long as checker is not null  you may use  checker as posted  This is possible since Java 5  because this Boolean variable will be autoboxed to the primivite boolean value

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As object   equals  public boolean equals Object obj   Returns true if and only if the argument is not null and is a Boolean object that represents the same boolean value as this object   Overrides      equals in class Object  Parameters      obj - the object to compare with   Returns      true if the Boolean objects represent the same value  false otherwise   boolean a   true  boolean b   false   System out println  a equals b        Object a  equals    Object b        Output  a equals b  false

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Regarding the performance of the direct operations and the method  equals    The  equals   methods seems to be roughly 4 times slower than      I ran the following tests    For the performance of      public class BooleanPerfCheck        public static void main String   args            long frameStart          long elapsedTime           boolean heyderr   false           frameStart   System currentTimeMillis             for  int i   0  i  lt  999999999  i                  if  heyderr    false                                     elapsedTime   System currentTimeMillis   - frameStart          System out println elapsedTime             and for the performance of  equals     public class BooleanPerfCheck        public static void main String   args            long frameStart          long elapsedTime           Boolean heyderr   false           frameStart   System currentTimeMillis             for  int i   0  i  lt  999999999  i                  if  heyderr equals false                                      elapsedTime   System currentTimeMillis   - frameStart          System out println elapsedTime             Total system time for    was 1  Total system time for  equals   varied from 3 - 5  Thus  it is safe to say that  equals   hinders performance and that    is better to use in most cases to compare Boolean

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Try this   if  Boolean TRUE equals yourValue             As additional benefit this is null-safe

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equals false  will be slower because you are calling a virtual method on an object rather than using faster syntax and rather unexpected by most of the programmers because code standards that are generally used don t really assume you should be doing that check via  equals false  method

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From your comments  it seems like you re looking for  best practices  for the use of the Boolean wrapper class   But there really aren t any best practices  because it s a bad idea to use this class to begin with   The only reason to use the object wrapper is in cases where you absolutely must  such as when using Generics  i e   storing a boolean in a HashMap lt String  Boolean gt  or the like    Using the object wrapper has no upsides and a lot of downsides  most notably that it opens you up to NullPointerExceptions      Does it matter if     is used instead of  equals   for Boolean    Both techniques will be susceptible to a NullPointerException  so it doesn t matter in that regard   In the first scenario  the Boolean will be unboxed into its respective boolean value and compared as normal   In the second scenario  you are invoking a method from the Boolean class  which is the following   public boolean equals Object obj        if  obj instanceof Boolean            return value      Boolean obj  booleanValue              return false      Either way  the results are the same      Would it matter if  equals false  was used to check for the value of the Boolean checker    Per above  no      Secondary question  Should Boolean be dealt differently than boolean    If you absolutely must use the Boolean class  always check for null before performing any comparisons   e g    Map lt String  Boolean gt  map   new HashMap lt String  Boolean gt          stuff to populate the Map Boolean value   map get  someKey    if value    null  amp  amp  value          do stuff     This will work because Java short-circuits conditional evaluations   You can also use the ternary operator   boolean easyToUseValue   value    null   value   false    But seriously    just use the primitive type  unless you re forced not to

[java] How to compare Boolean?

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