ruby 嵌套函数

嵌套循环 (Nested for loop)

Nesting of for loop means one for loop is available inside another for loop. It means that there are two loops, then the first one is an outer loop and the second one is the inner loop. Execution will take place in the manner that first the outer for loop is triggered, then if the condition is matched the pointer will be passed to the inner loop. Here also if the condition is satisfied, the inner for loop body will be executed until specified condition does not comes out to be false. Once the inner loop completes its execution, the pointer will be passed back to the outer for loop for its successful execution.

嵌套for循环意味着一个for循环可在另一个for循环内使用 。 这意味着有两个循环，然后第一个是外部循环，第二个是内部循环。 执行将以首先触发外部for循环的方式进行，然后如果条件匹配，则指针将被传递到内部循环。 同样，如果满足条件，则将执行内部for循环主体，直到指定条件不为假为止。 内部循环完成执行后，指针将被传递回外部for循环以成功执行。

In Ruby, Nesting of for loop can be done with the help of the following syntax:

在Ruby中，可以使用以下语法来完成for循环的嵌套 ：

    for variable_name[, variable...] in expression [do]
#expressions
for variable_name[, variable...] in expression [do]
# code to be executed
end
#expressions
end

Example 1:

范例1：

=begin
Ruby program to demonstrate nested for loop
=end
puts "Enter upper limit"
ul=gets.chomp.to_i
puts "Enter Lower limit"
ll=gets.chomp.to_i
for i in ll..ul do
for i in 0..3 do
puts "Inner loop triggered"
end
puts "Outer loop triggered"
end

Output

输出量

Enter upper limit
90
Enter Lower limit
85
Inner loop triggered
Inner loop triggered
Inner loop triggered
Inner loop triggered
Outer loop triggered
Inner loop triggered
Inner loop triggered
Inner loop triggered
Inner loop triggered
Outer loop triggered
Inner loop triggered
Inner loop triggered
Inner loop triggered
Inner loop triggered
Outer loop triggered
Inner loop triggered
Inner loop triggered
Inner loop triggered
Inner loop triggered
Outer loop triggered
Inner loop triggered
Inner loop triggered
Inner loop triggered
Inner loop triggered
Outer loop triggered
Inner loop triggered
Inner loop triggered
Inner loop triggered
Inner loop triggered
Outer loop triggered

You can observe in the above example that first the outer for loop is invoked then the pointer has moved to inner loop and it is printing the message for times.

您可以在上面的示例中观察到，首先调用了外部for循环，然后指针移至了内部循环，并且多次打印该消息。

Once the inner for loop completes its task, the pointer goes back to the outer loop.

内部for循环完成其任务后，指针将返回到外部循环。

Example 2:

范例2：

Patterns can also be printed using nested for loop. Now let us have a quick view of how the following pattern can be printed.

也可以使用嵌套的for循环来打印图案。 现在让我们快速了解如何打印以下图案。

*
**
***
****
*****

Code:

码：

=begin
Ruby program to print a pattern using nested for loop
=end
for i in 1..5 do
for j in 1..i do
print "*"
end
puts ""
end

翻译自: https://www.includehelp.com/ruby/nested-for-loop-with-examples.aspx

ruby 嵌套函数