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One I've never thought of using before is the: isAwesome && alert("yay"); I have used the name || "no name" operator a lot and thought to myself that it looked

by fedlarm 12y ago

One I've never thought of using before is the: isAwesome && alert("yay"); I have used the name || "no name" operator a lot and thought to myself that it looked cool on first impression. But having something like: isAwesome() && alert("yay"); Already makes it harder to read I think. I'm curious to what others think of this one? Maybe its just because it is new to me..

xyclos 12y ago
it is also useful for cross browser debugging. having a console.log() in your code running in IE will cause problems if the console isn't actually open. If you use window.console&&console.log() you can be sure that it wont hurt your code running in IE.
JonnieCache 12y ago
I agree that it's ugly, but also in some languages you can get into trouble because of operator precedence. This is why ruby and perl have the operators `or` and `and` as well as || and &&. http://devblog.avdi.org/2010/08/02/using-and-and-or-in-ruby/ http://devblog.avdi.org/2010/08/02/using-and-and-or-in-ruby/
byerley 12y ago
I don't think I've ever misread that style (usually the function being called makes it obvious), but it relies on short-circuit evaluation which doesn't carry over to a lot of languages - http://en.wikipedia.org/wiki/Short-circuit_evaluation http://en.wikipedia.org/wiki/Short-circuit_evaluation C is particularly dangerous because it will normally short-circuit, but the standard doesn't require it and in rare cases the compiler will optimize it out.
digibo 12y ago
I find constructs like isAwesome() && alert("yay"); confusing as well, but in our codebase it's pretty much standard to use a simple falsy check like 'callback && callback()' for optional callbacks, but we don't use it anywhere else. To be honest, I like and use some of those, especially when writing experimental/disposable code, but otherwise I try to be gentle to less experienced developers and my future self. As of #5 - I used to do and love this when writing unit tests. At the end of the work day, if I'm in the middle of implementing a feature, I'd commit and then write the next unit test (inevitably) sitting in my head and leave it failing. Really helps when it's Monday.

by fedlarm 12y ago

xyclos 12y ago

it is also useful for cross browser debugging. having a console.log() in your code running in IE will cause problems if the console isn't actually open. If you use window.console&&console.log() you can be sure that it wont hurt your code running in IE.

JonnieCache 12y ago

I agree that it's ugly, but also in some languages you can get into trouble because of operator precedence. This is why ruby and perl have the operators `or` and `and` as well as || and &&. http://devblog.avdi.org/2010/08/02/using-and-and-or-in-ruby/ http://devblog.avdi.org/2010/08/02/using-and-and-or-in-ruby/

byerley 12y ago

I don't think I've ever misread that style (usually the function being called makes it obvious), but it relies on short-circuit evaluation which doesn't carry over to a lot of languages - http://en.wikipedia.org/wiki/Short-circuit_evaluation http://en.wikipedia.org/wiki/Short-circuit_evaluation C is particularly dangerous because it will normally short-circuit, but the standard doesn't require it and in rare cases the compiler will optimize it out.

digibo 12y ago

I find constructs like isAwesome() && alert("yay"); confusing as well, but in our codebase it's pretty much standard to use a simple falsy check like 'callback && callback()' for optional callbacks, but we don't use it anywhere else. To be honest, I like and use some of those, especially when writing experimental/disposable code, but otherwise I try to be gentle to less experienced developers and my future self. As of #5 - I used to do and love this when writing unit tests. At the end of the work day, if I'm in the middle of implementing a feature, I'd commit and then write the next unit test (inevitably) sitting in my head and leave it failing. Really helps when it's Monday.