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.