What context can I use each word in?
Learn when and how to use these words with these examples!
idempotent
Example
The idempotent property of addition means that 2 + 2 = 4, and 2 + 2 + 2 + 2 = 4 as well. [idempotent: adjective]
Example
The HTTP method DELETE is idempotent because it will return the same result whether called once or multiple times. [idempotent: adjective]
Example
Rebooting the computer is an idempotent operation since it has no additional effect if done multiple times. [idempotent: noun]
invariant
Example
The speed of light is an invariant in physics, meaning it remains constant regardless of the observer's motion. [invariant: noun]
Example
The sorting algorithm is invariant to the order of input elements, producing the same output regardless of their initial arrangement. [invariant: adjective]
Example
The conservation of energy is an invariant principle in nature, stating that energy cannot be created or destroyed, only transformed. [invariant: noun]
Good things to know
Which word is more common?
Invariant is more commonly used than idempotent in everyday language, especially in mathematics and natural sciences. Idempotent is a technical term with a narrower usage, mostly in computing and programming.
What’s the difference in the tone of formality between idempotent and invariant?
Both idempotent and invariant are technical terms that are more likely to be used in formal or academic contexts than in casual conversation. However, idempotent is more specific to computing and programming, while invariant has wider applications in various fields of study.
