How to read keyboard input in C

We can use the scanf() function to get user input in C. Here’s a quick implementation of scanf():

scanf() will wait for the user to press Enter before giving its returned value back to our app. We must define a variable to hold its output. We can even define multiple variables, each of which will be populated with whatever is being typed in until Enter is pressed. Consider this:

Here we wait for three string items to be added (numbers entered will be interpreted as strings). To grab a numeric value from the keyboard, we cam use %d like so (d as in decimal, variable defined as int):

Note the ampersand in front of our variable, without which scanf would populate a pointer. We can also mix and match keyboard input like this:

Demo Project

You’ll find a quick demo project on GitHub, which also serves as a template on how to setup Xcode to open Terminal and allow for keyboard input when the project is run.

About Jay Versluis

Jay is a medical miracle known as Super Survivor. He runs two YouTube channels, five websites and several podcast feeds. To see what else he's up to, and to support him on his mission to make the world a better place, check out his Patreon Campaign.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.