Ruby 循环语句

# while 语句

$i = 0
$num = 10

while $i < $num
    $i += 1
    puts $i
end

puts ()

# while 修饰符
    # 像 C 的 do while 语句
$a = 0
$b = 5
begin
    puts "在循环语句中 a = #{$a}"
    $a += 1
end while $a < $b

puts ()

# until 语句
$c = 0
$d = 5
until $d < $c
    puts "在循环语句中 d = #{$d}"
    $d -= 1
end

puts ()

# until 修饰符
    # 条件为假, 执行
$e = 0
$f = 5
begin
    puts "在循环语句中 e = #{$e}"
    $e += 1
end until $e > $f



puts ()

# for 语句
for g in 0 .. 5
    puts "g = #{g}"
end

puts ()

(0 .. 5).each do |h|
    puts "局部变量的值为 #{h}"
end

# next 相当于 continue

for i in 0 .. 5
    if i < 2
        next
    end
    puts i
end


# redo 语句
    # 重新开始最内部循环的该次迭代, 不检查循环条件. 如果在块内调用, 则重新开始 yield 或 call.

$i = 0
for i in 0 .. 5
    if i < 2 
        puts i
        if $i < 10 
            $i += 1
        else
            break
        end
        redo
    end
end