Ruby语法笔记

接受用户输入

first_name = gets.chomp

首字母大写

first_name.capitalize!

字母变大写

first_name.upcase!

字母变小写

first_name.downcase!

多行输出

print <<EOF  # 多行输出EOF

注释

# 我是注释

变量获取

#{first_name}

变量

全局变量 $ 类变量 @@ 方法变量 @ 局部变量 小写字母或_

if/else

if a < b  puts '1'elsif b < a  puts '2'end    

类

class Classname  def functionname(params)    puts params  endendclass1 = Classname.newclass1.functionname('1')unlessunless false  print 'ok'else  print 'no'end    

是否包含字符

print 'puts'user_input = gets.chompuser_input.downcase!if user_input.include?"s"  print 'has s'end

替换字符

# s -> thuser_input.gsub!(/s/,"th")

在字符串中输出变量值

puts 'okok #{user_input}'

while

counter = 1while counter < 11  puts counter  counter = counter + 1end

Until

counter = 1until counter > 10  print counter  counter = counter + 1end  

+= 、 -= 、 *=、 /=
Some languages have the increment operators ++ and -- (which also add or subtract 1 from a value), but Ruby does not
for循环
# 如果 1...10 包含1-9，如果 1..10 包含1-10

for num in 1...10  puts numend  

Loop Method
An iterator is just a Ruby method that repeatedly invokes a block of code.

i = 20loop do  i -= 1  print "#{ i }"  break if i <= 0end  

Next

i = 20loop do i -= 1 next if i%2 != 0 print "#{i}" break if i <= 0end

数组

my_array = [1,2,3,4,5]

The .each Iterator迭代器

numbers = [1, 2, 3, 4, 5]# one way to loopnumbers.each { |item| puts item }# another way to loopnumbers.each do |item| puts itemend

The .times Iterator 次数迭代器

10.times { print 'ok'})

Looping with 'While'

num = 1while num <= 50 do  print num  num += 1end  

Looping with 'Until'

num = 1until num > 50 do  print num  num += 1end  

Loop the Loop with Loop

num = 0loop do  num += 1  print "Ruby!"  break if num == 30end