As one would expect, the case sensitive ones require a backslash before the number. The way the backslashes work is that you use them to escape special characters, which are the ones that are case sensitive.
You can get around this problem by using a backslash before a lowercase letter. For instance, the string “foo bar” is the same string as “foo\ bar” because a backslash is used before a lowercase letter.
But that doesn’t solve the case sensitive issue, because the variable string that is returned by a string function can’t have a case sensitive value. In other words, the string foo bar will return the same string that the same variable string that was passed in will return.
This is more than just a silly little fact, as case-insensitivity can be a massive performance improvement when it comes to certain applications, such as web-based email clients, where users can’t expect to see all of their messages in one window. A case-insensitive string is one that is interpreted by the browser as it would be in the computer’s native language.