ruby推送示例
for循環 (The for loop)
In programming, for loop is a kind of iteration statement which allows the block to be iterated repeatedly as long as the specified condition is not met or a specific number of times that the programmer knows beforehand. A for loop is made of two parts:
在編程中， for循環是一種迭代語句，只要不滿足指定條件或程序員事先知道的特定次數，就可以重復迭代該塊。 for循環由兩部分組成：
The header part
標頭部分
The actual body
實際的身體
The header part is used to specify the number of iterations. Most of the times it explicitly mentions the count of iterations with the help of a variable. for loop is generally used when the number of iterations is explicitly known before the execution of the statement declared within its block. The actual body contains the expressions or statements which will be implemented once per repetition.
標頭部分用于指定迭代次數。 在大多數情況下，它借助變量明確提及迭代次數。 當在其塊內聲明的語句執行之前明確知道迭代次數時，通常使用for循環 。 實際主體包含將重復執行一次的表達式或語句。
It is a kind of Entry control loop. Generally, you can easily make an infinite loop through for loop by using the following syntax:
這是一種Entry控制循環。 通常，您可以使用以下語法輕松地通過for循環進行無限循環：
for(;;)
{
#body
}
In Ruby, for loop is implemented with the help of the following syntax:
在Ruby中， for循環是通過以下語法實現的：
for variable_name[, variable...] in expression [do]
# code to be executed
end
Example 1:
范例1：
=begin
Ruby program to print the table of the number
specified by the user using for loop
=end
puts "Enter a number"
num=gets.chomp.to_i
for i in 1..10 #implementation of for loop for
#pre-specified range 1..10
k=i*num
puts "#{num} * #{i} = #{k}"
i+=1 #incrementing the counter variable
end
Output
輸出量
Enter a number
89
89 * 1 = 89
89 * 2 = 178
89 * 3 = 267
89 * 4 = 356
89 * 5 = 445
89 * 6 = 534
89 * 7 = 623
89 * 8 = 712
89 * 9 = 801
89 * 10 = 890
Example 2:
范例2：
=begin
Ruby program to print the list of the odd and even
numbers where the lower limit is specified by the user
and the upper limit is 100 using for loop
=end
puts "Enter the lower limit(ul is 100)"
num=gets.chomp.to_i
if (num>=100) #lower limit can not be
#equal to or greater than upper limit
puts "Invalid lower limit"
else
for i in num..100 #implementation of for loop for
#pre-specified range num..100
if (i%2==0)
puts "#{i} is even"
else
puts "#{i} is odd"
end
i=i+1 #incrementing the counter variable
end
end
Output
輸出量
First run:
Enter the lower limit
76
76 is even
77 is odd
78 is even
79 is odd
80 is even
81 is odd
82 is even
83 is odd
84 is even
85 is odd
86 is even
87 is odd
88 is even
89 is odd
90 is even
91 is odd
92 is even
93 is odd
94 is even
95 is odd
96 is even
97 is odd
98 is even
99 is odd
100 is even
Second run:
Enter the lower limit
900
Invalid lower limit
The for loop is one of the most commonly used loops in programming. As it is preferable and has easy syntax.
for循環是編程中最常用的循環之一。 最好是它并且語法簡單。
翻譯自: https://www.includehelp.com/ruby/for-loop.aspx
ruby推送示例
