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Unity - Using the Assert Class for Debugging

June 5, 2022Updated Feb 17, 2026

Unity's Assert class is used for assertion-based debugging.

Syntax:

Assert.IsTrue(condition);
Assert.IsFalse(condition);
Assert.AreEqual(expected, actual);
Assert.IsNull(obj);
Assert.IsNotNull(obj);

Example:

void Update() {
Assert.IsNotNull(player);
Assert.IsTrue(health > 0);
}

Assertions are only evaluated in the Editor and Development Builds. They are stripped from Release Builds.

Benefits:

  • Catch logic errors early
  • Document expected conditions
  • Aid in debugging

Note: Do not use assertions for handling user input or expected errors. Use try-catch or validation logic instead.