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    <pre><code>equal? is reference equality == is value equality eql? is value and type equality </code></pre> <p>The third method, <code>eql?</code> is normally used to test if two objects have the same value as well as the same type. For example:</p> <pre><code>puts "integer == to float: #{25 == 25.0}" puts "integer eql? to float: #{25.eql? 25.0}" gives: Does integer == to float: true Does integer eql? to float: false </code></pre> <p>So I thought since <code>eql?</code> does more checking it would be slower, and for strings it is, at least on my Ruby 1.93. So I figured it must be type dependent and did some tests. When integer and floats are compared <code>eql?</code> is a bit faster. When integers are compared <code>==</code> is much faster, until x2. Wrong theory, back to start.</p> <p>The next theory: comparing two values of the same type will be faster with one of both proved to be true, in the case they are of the same type <code>==</code> is always faster, <code>eql?</code> is faster when types are different, again until x2.</p> <p>Don't have the time to compare all types but I'm sure you'll get varying results, although the same kind of comparison always gives similar results. Can somebody prove me wrong?</p> <p>Here are my results from the test of the OP:</p> <pre><code> 16.863000 0.000000 16.863000 ( 16.903000) 2 strings with eql? 14.212000 0.000000 14.212000 ( 14.334600) 2 strings with == 13.213000 0.000000 13.213000 ( 13.245600) integer and floating with eql? 14.103000 0.000000 14.103000 ( 14.200400) integer and floating with == 13.229000 0.000000 13.229000 ( 13.410800) 2 same integers with eql? 9.406000 0.000000 9.406000 ( 9.410000) 2 same integers with == 19.625000 0.000000 19.625000 ( 19.720800) 2 different integers with eql? 9.407000 0.000000 9.407000 ( 9.405800) 2 different integers with == 21.825000 0.000000 21.825000 ( 21.910200) integer with string with eql? 43.836000 0.031000 43.867000 ( 44.074200) integer with string with == </code></pre>
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    1. POWhy is == faster than eql?
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    1. CO"So i thought since eql ? does more checking it would be slower" - except it **doesn't** do more checking; look at the C source code that the OP posted (or look it up on rubydoc.org: [==](http://www.ruby-doc.org/core-1.9.3/String.html#method-i-3D-3D) vs. [eql?](http://www.ruby-doc.org/core-1.9.3/String.html#method-i-eql-3F)).
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    2. COi know abe, edit my answer a bit to make that clear. Was just forming a theory based on the documentation and tested it, proved to be wrong perhaps cause the reason you'r mentioning, my second theory still stands until counter evidence, i agree it doesn't really answer WHY but it's a start isn't it ?
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    3. COFair enough, I wasn't trying to sound like a jerk just pointing out that the C source doesn't match the == vs. eql? assumption
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