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Comment by heyitsnick | Hacker News Reader

It's a shame it didn't mention the _reason_ for Yoda Conditions: as a protection against accidentally using the assignment operator rather than a check for equality. Accidentally writing if (foo=4) { } will not raise an exception, whereas if (4=foo) {} does, thus alerting you of your typo rather than allowing a rather nasty bug to persist.

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Of course, any compiler written in the past decade should print a warning on if (foo = 4), so this reason doesn't apply much any more.

I use them when doing an assignment and equality check in the same if statement. I find that putting the equality check first helps readability and makes the intent clearer.

eg.

    if (null == (data = cache.get('blah')))
      // cache miss
    else
      // cache hit

I used to find lots of yoda conditions in Java. People use it to test a string variable against a constant value and save some null checks.

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