Advanced
TypeScript
Q100 / 100
What is "type narrowing via assignment" and how does control flow analysis use it, e.g. "let x: string | number = getValue(); x = 5;"?
Correct! Well done.
Incorrect.
The correct answer is B) After the assignment "x = 5", TypeScript narrows the type of x to "number" for subsequent code in that flow, based on the assigned value's type
B
Correct Answer
After the assignment "x = 5", TypeScript narrows the type of x to "number" for subsequent code in that flow, based on the assigned value's type
Explanation
TypeScript's control flow analysis tracks the type of a variable through assignments, narrowing it to the type of the most recently assigned value within the reachable code path.
Progress
100/100