check vs validate vs verify vs assert
Check is informal and returns a boolean. Validate is for enforcing rules on input at system boundaries. Verify is for cross-checking against an external source. Assert is a hard statement that fails immediately if false.
check
Informal and lightweight. Look at something to see if it meets a condition. A check usually returns a boolean and does not throw. Used in everyday conversation and code.
"if (checkPermissions(user)) { ... } // returns true/false, no side effects"
validate
Confirm that input meets a set of rules or constraints. Used at system boundaries: forms, API requests, user input. Validation usually returns errors or a structured result, not just a boolean.
"const errors = validateUserInput(formData); // returns structured error list"
verify
Confirm that something is true or correct, often by cross-checking with an external source. Used in security (verify a token, verify a signature) and formal testing.
"verify(jwt, SECRET_KEY) // checks signature against a trusted source"
assert
Make a hard statement that must be true. If it is not, execution stops or the test fails immediately. Used in test assertions and defensive programming.
"assert response.status_code == 200, 'Expected 200 but got ' + str(response.status_code)"
Other comparisons
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