Ruby中的if语句冲突

Question

我尝试在支持Ruby 1.8.7的在线IDE中运行此代码,并且该elsif语句未被识别; 例如,如果我输入"85",它仍然会返回"超重".

def prompt
 print ">> "
end

puts "Welcome to the Weight-Calc 3000! Enter your weight below!"

prompt; weight = gets.chomp()

if weight > "300" 
 puts "Over-weight"
elsif weight < "100"
 puts "Under-weight"
end

但是,当我运行以下操作时,它可以正常工作:

def prompt
 print ">> "
end

puts "Welcome to the Weight-Calc 3000! Enter your weight below!"

prompt; weight = gets.chomp()

if weight > "300" 
 puts "Over-weight"
elsif weight > "100" && weight < "301"
 puts "You're good."
end

关于如何解决这个问题的任何想法？

Answer 1

问题是你试图比较从左到右评估的字符串,而不是数字.

将它们转换为整数(或浮点数),并进行比较.

weight = Integer(gets.chomp())

if weight > 300
 puts "Over-weight"
elsif weight < 100
 puts "Under-weight"
end

Answer 2

同

if weight > "300"

你正在比较两个字符串.

它应该是

if weight.to_i > 300