什么是逻辑算子?
Consider using parentheses to improve readability and avoid mistakes because of logical operator precedence.
考虑使用括号来改善可读性和避免由于逻辑操作符的优先级导致的错误。
A logical operator that consists of a logical and followed by a logical NOT and returns a false value only if both operands are true.
由逻辑与和其后的逻辑非组成的逻辑运算符,如果两个运算域都是真,则返回的值便为假。
The logical operators have lower precedence than the individual comparison operators, which makes sense because the comparison has to be evaluated before the logical operator can be evaluated.
逻辑运算符的优先级低于单独的比较运算符,这一点意义重大,因为必须先计算比较运算符,然后才能计算逻辑运算符。
It's best to read such execution plans from the left-lowest operator in the tree, since the logical flow in the plan is from bottom to top and left to right.
因为执行计划中的逻辑流是自下而上、从左到右,所以看此类执行计划时,最好是从树中左下方的操作符开始。
If you use the logical | | operator, Perl will use the first true value it comes across, in order, from left to right.
如果使用逻辑| |操作符,Perl就会使用后面的第一个真值,顺序从左到右取值。
The next step is to choose the logical and or or operator and a second parameter.
下一步骤是选择逻辑AND或OR操作符和第二个参数。
This is the normal logical or are used to; it's just a function, not an operator.
这是常用的 or逻辑;它是一个函数,而不是一个操作符。
The result of the logical negation operator!
的逻辑否定运算符的结果!
The result of the logical negation operator!
的逻辑否定运算符的结果!
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