Simplify if

From time to time we write unoptimized code. For program to be cute it is fun to be optimized.
For example this is a possible way to write if sequence:

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1. if (p.equals("Completed")){  
2.    return true;  
3. } else {  
4.    return false;  
5. }  

if (p.equals("Completed")){
   return true;
} else {
   return false;
}

But to be optimized the method body should look like this:

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1. return "Completed".equals(p);  

return "Completed".equals(p);

What's really interesting is that it's not only looking good. Indeed it helps you to evade null pointer exception in case when p equals null. We are not able to call method from null - it'll throw exception, but when using equals() method this would be processed correctly.

To study this in depth we can explore StringUtils.java (the one that is in org.apache.commons.lang package).

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1. public static boolean equals(String str1, String str2) {  
2.    return str1 == null ? str2 == null : str1.equals(str2);  
3. }  

public static boolean equals(String str1, String str2) {
   return str1 == null ? str2 == null : str1.equals(str2);
}

Lets look at the method in JAVA source code and the values it may return:

StringUtils.equals(null, null) = true
StringUtils.equals(null, "abc") = false
StringUtils.equals("abc", null) = false
StringUtils.equals("abc", "abc") = true
StringUtils.equals("abc", "ABC") = false

It returns true in case of equality. So, we can use this or the same logic to write our optimized pieces of code.

Have fun, optimize :)