爲什麼這個「聾奶奶」程序不正確？

Question

此代碼將返回基於整個字符串是否是大寫

response = '' 

while response != "BYE" 
    puts "What would you like deary?" 
    response = gets.chomp 
    if response = response.downcase 
     puts "speak up!" 
    else 
     puts "I can hear you!" 
    end 
    response = gets.chomp 
end 

此代碼，但是，總是返回正確的短語「說話」，無論輸入的字符串是否是全小寫或全部大寫：

puts "What would you like deary?" 
response = gets.chomp 

while response != "BYE" 
    if response = response.downcase 
     puts "speak up!" 
    else 
     puts "I can hear you!" 
    end 
    response = gets.chomp 
end 

我有點困惑，爲什麼會發生這種情況。

Answer 1

看起來要測試相等（==），不進行分配（=）：

if response == response.downcase