PHP字符串比较单引号和双引号之间有什么不同？ [关闭]

This is a simple but tricky

Question is Is there different in following two IF Statement comparisons (Note Quotes)

if ($retry_type == 'new')

AND

if ($retry_type == "new")

I know there is difference between

printf("something $var")

AND

printf('something $var')

In your example, there's no difference.

There is one other difference besides the ability to interpolate variables, though: In a single-quoted string, the only escape sequences that mean anything are \' and \\. All others are ignored; for example, ' ' actually consists of a backslash and a 'n', whereas " " is interpreted as a newline.

Nope. A string is a string.

only exception is that if you use double quotes, you can throw in $variables too.

Consider the following example:

var_dump('new' === "new");

Run it. Examine it. Answer your own question.