Name
keyPressed()
Description
The keyPressed() function is called once every time a key is
pressed. The key that was pressed is stored in the key variable.
For non-ASCII keys, use the keyCode variable. The keys included in
the ASCII specification (BACKSPACE, TAB, ENTER, RETURN, ESC, and DELETE) do
not require checking to see if the key is coded; for those keys, you should
simply use the key variable directly (and not keyCode). If
you're making cross-platform projects, note that the ENTER key is commonly
used on PCs and Unix, while the RETURN key is used on Macs. Make sure your
program will work on all platforms by checking for both ENTER and RETURN.
Because of how operating systems handle key repeats, holding down a key may
cause multiple calls to keyPressed(). The rate of repeat is set by
the operating system, and may be configured differently on each computer.
Note that there is a similarly named boolean variable called
keyPressed. See its reference page for more information.
Mouse and keyboard events only work when a program has draw().
Without draw(), the code is only run once and then stops listening
for events.
With the release of macOS Sierra, Apple changed how key repeat works, so
keyPressed may not function as expected. See here
for details of the problem and how to fix it.
Examples
// Click on the image to give it focus, // and then press any key. int value = 0; void draw() { fill(value); rect(25, 25, 50, 50); } void keyPressed() { if (value == 0) { value = 255; } else { value = 0; } }
Syntax
keyPressed()keyPressed(event)
Return
void
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