= SDL_assert =
Use this macro to create an assertion for debugging.


== Syntax ==
<syntaxhighlight lang='c++'>
void SDL_assert(condition)
</syntaxhighlight>

== Function Parameters ==
{|
|'''condition'''
|the expression to check
|}

== Code Examples ==
<syntaxhighlight lang='c++'>
SDL_assert(1 == 0);  // triggers an assertion.
SDL_assert(1 == 1);  // does NOT trigger an assertion.
</syntaxhighlight>

== Remarks ==
This function is enabled only when the SDL_ASSERT_LEVEL is set to 2 or 3, otherwise it is disabled.  See the [[CategoryAssert|Assertions Category page]] for details.

One can set the environment variable "SDL_ASSERT" to one of several strings ("abort", "break", "retry", "ignore", "always_ignore") to force a default behavior, which may be desirable for automation purposes. If your platform requires GUI interfaces to happen on the main thread but you're debugging an assertion in a background thread, it might be desirable to set this to "break" so that your debugger takes control as soon as assert is triggered, instead of risking a bad UI interaction (deadlock, etc) in the application.

Note that the SDL_ASSERT environment variable is an ''environment variable'' and not an SDL hint! Please refer to your platform's documentation for how to set it!

== Related Functions ==
:[[SDL_assert_paranoid]]
:[[SDL_assert_release]]

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[[CategoryAPI]], [[CategoryAPIFunction]], [[CategoryAssert]]