"PHP" encountered some special characters "ESC" "BEL"

I have a code here.

$str =strtr ($str, Array (    "\ n"  and "\\n", "    " = = "", "    " = = "));

In fact, the two on the array is not a space character, you can copy the code into the sublime text inside to display, you will find as shown



Here's a question,
How do we make these two characters?
What does each of these characters mean?

Reply to discussion (solution)

ESC chr (0x1b) escape
BEL chr (7) 0x07 Bell
are ASCII control characters

Thank you, I have just found the answer.

