Perl句点与逗号运算符
为什么Perl句点与逗号运算符,perl,comma,period,Perl,Comma,Period,为什么 print "$str is " , ispalindrome($str) ? "" : " not" , " a palindrome\n" 打印“女士是回文”,但是 打印“”?条件运算符(?:)的优先级高于逗号,但低于句点。因此,第一行被解析为: print("$str is " , (ispalindrome($str) ? "" : " not"), " a palindrome\n") print(("$str is " . ispalindrome($str)) ? "
print "$str is " , ispalindrome($str) ? "" : " not" , " a palindrome\n"
打印“女士是回文”,但是
打印“”?条件运算符(?:
)的优先级高于逗号,但低于句点。因此,第一行被解析为:
print("$str is " , (ispalindrome($str) ? "" : " not"), " a palindrome\n")
print(("$str is " . ispalindrome($str)) ? "" : (" not" . " a palindrome\n"))
而第二个被解析为:
print("$str is " , (ispalindrome($str) ? "" : " not"), " a palindrome\n")
print(("$str is " . ispalindrome($str)) ? "" : (" not" . " a palindrome\n"))