logical-operators

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What is the exact meaning of this code using the || ("OR") operator?

I saw somewhere this code snippet: var idx = SOME_VALUE; var color = { yellor: 1, red: 2, black: 0 }; var x = color[idx] || []; // Is 开发者_运维百科this means if color[idx] is null, then return an[详细]

2023-02-27 00:27 分类：问答
Does JavaScript have non-shortcircuiting boolean operators?

In JavaScript (f1() || f2()) won\'t execute f2 if f1 returns true which is usually a good thing except for when it isn\'t. Is there a version of || that doesn\'t short circuit?[详细]

2023-02-24 04:28 分类：问答
PHP eval() logical operator error

Why does if (isset($_SESSION[\'location\']) AND !empty($_SESSION[\'location\'])) work while if (isset($_SESSION[\'location\']) && !empty($_SESSION[\'location\']))[详细]

2023-02-19 15:41 分类：问答
Why don't logical operators (&& and ||) always return a boolean result?

Why do these logical operators return an object and not a boolean? var _ = (obj.fn && obj.fn() ) || obj._ || ( obj._ = {} );[详细]

2023-02-19 05:27 分类：问答
Logical OR will not work in if statement

this is what i have: <?php if($row[\'id\']!=\"9\") echo \"style=\\\"display:none\\\"\"; ?> simple enough, it should place style=\"dsplay:none\" when \'i开发者_运维问答d\' is anything but 9. t[详细]

2023-02-18 07:00 分类：问答
How to write "if x equals 5 or 4 or 78 or..." in C

I have a quick question about using logical operators in an if statement. Currently I have an if statement that checks if x equals to 5 or 4 or 78:[详细]

2023-02-16 21:48 分类：问答
Do PHP's logical operators work as JavaScript's?

One of the things I like the most of JavaScript is that the logical operators are very powerful: && can be used to safely extract the value of an object\'s 开发者_StackOverflowfield, and wil[详细]

2023-02-16 03:20 分类：问答
Overloading logical operators considered bad practice?

Is it a bad idea to overload &&, || or comma operator and Wh开发者_开发百科y?I wouldn\'t overload operator&& or operator||. Even if you define a class that gives rise to a Boolean alge[详细]

2023-02-13 13:05 分类：问答
Could this `if` statement generate a Null-Reference Exception ever?

I think my point is clear, under any condition, could this throw null-reference exception? i.e. objecting that e.Result is null while trying to access its Count property.[详细]

2023-02-13 09:31 分类：问答
PHP - not operator, any other aliases?

if(!($whatever && what()) do_stuff... Can this be replaced with something more intuitive like:[详细]

2023-02-08 16:10 分类：问答