ruby 2.6.1_Ruby do ... while循环示例

ゝ一世哀愁。 2023-03-05 11:58 18阅读 0赞

ruby 2.6.1

## do while循环 **(**The do while loop**)** ##

In programming, **do...while loop** works in the same way as a while loop with a basic difference that the specified Boolean condition is evaluated at the end of the block execution. This result in the execution of statements at least for once and later iterations depend upon the result of the Boolean expression. A process symbol and a Boolean condition is used to make a **do...while iteration**.

在编程中， **do ... while循环的**工作方式与while循环相同，基本区别是在块执行结束时评估指定的布尔条件。 这导致语句至少执行一次，以后的迭代取决于布尔表达式的结果。 使用过程符号和布尔条件进行**do ... while迭代** 。

In this loop, at first, the block defined inside the code is executed then the given condition is checked. Due to this property, it is also known as post-test loop.

在此循环中，首先，执行代码内部定义的块，然后检查给定条件。 由于此属性，它也称为测试后循环。

A **do...while loop** is an example of the **exit-control loop** because in this the code is executed before the evaluation of the specified condition. It runs till the Boolean condition stands to be true, once it evaluates to be false the loop gets terminated at that point of time.

**do ... while循环**是**退出控制循环的**一个示例，因为在这种情况下，代码是在评估指定条件之前执行的。 它一直运行到布尔条件为真为止，一旦评估为假，则该循环在该时间点终止。

In Ruby, the **do...while loop** is implemented with the help of the following syntax:

在Ruby中， **do ... while循环**是通过以下语法实现的：

loop do
            # code block to be executed
            break if Boolean_Expression #use of break statement
        end

**Example 1:**

**范例1：**

=begin 
    Ruby program to check whether the given 
    number is Armstrong or not using a do-while loop
    =end
    
    puts "Enter the number"
    num=gets.chomp.to_i
    
    temp=num
    sum = 0
    
    loop do
    	#implementation of the do-while loop
    	rem=num%10
    	num=num/10
    	sum=sum+rem*rem*rem
    	puts "Checking......"
    	if num==0
    		break
    	end
    end
    
    if(temp==sum)
    	puts "The #{temp} is Armstrong"
    else
    	puts "The #{temp} is not Armstrong"
    end

**Output**

**输出量**

First run:
    Enter the number
    135
    Checking......
    Checking......
    Checking......
    The 135 is not Armstrong
    
    Second run:
    Enter the number
    1
    Checking......
    The 1 is Armstrong

**Example 2:**

**范例2：**

=begin 
    Ruby program to check wether the given number 
    is having five or not using do-while loop
    =end
    
    puts "Enter the number"
    num=gets.chomp.to_i
    
    temp=num
    sum = 0
    flag=false #flag is a Boolean variable
    
    loop do
    	#implementation of the do-while loop
    	rem=num%10
    	num=num/10
    	if(rem==5)
    		flag=true #flag is made true if the presence is found
    	end
    	puts "Checking......"
    	if num==0
    		break
    	end
    end
    
    if(flag==true)
    	puts "We have found the presence of five in #{temp}"
    else
    	puts "We have not found the presence of five in #{temp}"
    end

**Output**

**输出量**

First run:
    Enter the number
    1234566
    Checking......
    Checking......
    Checking......
    Checking......
    Checking......
    Checking......
    Checking......
    We have found the presence of five in 1234566
    
    Second run:
    Enter the number
    198762
    Checking......
    Checking......
    Checking......
    Checking......
    Checking......
    Checking......
    We have not found the presence of five in 198762

> 翻译自: [https://www.includehelp.com/ruby/do-while-loop-with-examples.aspx][https_www.includehelp.com_ruby_do-while-loop-with-examples.aspx]

ruby 2.6.1

[https_www.includehelp.com_ruby_do-while-loop-with-examples.aspx]: https://www.includehelp.com/ruby/do-while-loop-with-examples.aspx