Learn Objective-C: Escape Sequences and Format Specifiers
NSLog
, and its corresponding C function printf()
, use escape sequences to print certain characters that are “invisible.” For iOS, include:
Sequence | Meaning |
---|---|
\b |
backspace |
\f |
Form Feed |
\n |
Newline |
\t |
Horizontal Tab |
\v |
Vertical Tab |
\\ |
Backslash |
\' |
Single Quote |
\" |
Double Quote |
\? |
Question Mark |
There are others, such as \a
for Alert, but they are rarely used, and don’t make an effect.
Format specifiers, however, are the percent character, followed by a letter, such as %d
or %f
that tell NSLog
or printf()
to print the value or result of a variable, value, and/or expression.
Click here for a list of C format specifiers.
Just think of them as types of placeholders, each designed to represent a different value.
This post is part of the Learn Objective-C in 24 Days course.