For example
例如
func(@param) do |f|
some code here
end
and
和
@param.each do |sth|
some code here
end
What does the absolute value sign do here? I don't understand these two pieces of code.
这里的绝对值符号是什么?我不理解这两段代码。
4 个解决方案
#1
4
It's the local variable within the block, so for the line:
它是块中的局部变量，因此对于行:
@param.each do |sth|
you're iterating over @param right, well each item in @param is referred to singularly as sth.
你在对@param进行迭代，@param中的每一项都被单独地称为sth。
So if @param refers to an array containing the numbers
所以如果@param指的是一个包含数字的数组
[1,3,5,4]
During the first iteration sth will be 1, then 3, then 5, then 4.
在第一次迭代中，sth将是1、3、5、4。
Same goes for :
同样适用于:
func(@param) do |f|
except now the local variable is called f! You could call it anything you want, even |ihavenoideawhatimdoing|
但是现在局部变量被称为f!你可以叫它任何你想要的名字，甚至| ihavenoidemdoing |
#2
2
It's a local variable, it is saying that for the block of code between do...end, the variable f is defined.
它是一个局部变量，它表示对于do之间的代码块。最后，定义变量f。
#3
2
It is a parameter to a block. The block is the part of the code between the do and the end. That block of code can use f or sth, which in your examples would probably have been set by func or each.
它是块的参数。块是do和end之间代码的一部分。这个代码块可以使用f或sth，在您的示例中，它们可能是由func或each设置的。
A tutorial on Ruby blocks will probably be helpful.
关于Ruby块的教程可能会有帮助。
Labmda calculus - more abstract, but it was the context in which I first saw these things.
Labmda的微积分——更抽象，但这是我第一次看到这些东西的背景。
#4
0
It signifies instance variables. You often see it interchanged if people are using attr_* methods like attr_accessor, which makes @someattr and self.some_attr equivalent in instance methods.
它表示实例变量。如果人们使用attr_*方法(比如attr_accessor，它创建了@someattr和self)，那么您经常会看到它的互换性。在实例方法中等效的some_attr。
#1
4
It's the local variable within the block, so for the line:
它是块中的局部变量，因此对于行:
@param.each do |sth|
you're iterating over @param right, well each item in @param is referred to singularly as sth.
你在对@param进行迭代，@param中的每一项都被单独地称为sth。
So if @param refers to an array containing the numbers
所以如果@param指的是一个包含数字的数组
[1,3,5,4]
During the first iteration sth will be 1, then 3, then 5, then 4.
在第一次迭代中，sth将是1、3、5、4。
Same goes for :
同样适用于:
func(@param) do |f|
except now the local variable is called f! You could call it anything you want, even |ihavenoideawhatimdoing|
但是现在局部变量被称为f!你可以叫它任何你想要的名字，甚至| ihavenoidemdoing |
#2
2
It's a local variable, it is saying that for the block of code between do...end, the variable f is defined.
它是一个局部变量，它表示对于do之间的代码块。最后，定义变量f。
#3
2
It is a parameter to a block. The block is the part of the code between the do and the end. That block of code can use f or sth, which in your examples would probably have been set by func or each.
它是块的参数。块是do和end之间代码的一部分。这个代码块可以使用f或sth，在您的示例中，它们可能是由func或each设置的。
A tutorial on Ruby blocks will probably be helpful.
关于Ruby块的教程可能会有帮助。
Labmda calculus - more abstract, but it was the context in which I first saw these things.
Labmda的微积分——更抽象，但这是我第一次看到这些东西的背景。
#4
0
It signifies instance variables. You often see it interchanged if people are using attr_* methods like attr_accessor, which makes @someattr and self.some_attr equivalent in instance methods.
它表示实例变量。如果人们使用attr_*方法(比如attr_accessor，它创建了@someattr和self)，那么您经常会看到它的互换性。在实例方法中等效的some_attr。