Dynamic imports with types in Typescript - Time & Space Complexity

Time Complexity: Dynamic imports with types

O(n)

Understanding Time Complexity

When we use dynamic imports with types in TypeScript, we want to know how the time to load modules changes as we add more imports.

We ask: How does the program's loading time grow when importing modules dynamically?

Scenario Under Consideration

Analyze the time complexity of the following code snippet.

async function loadModule(name: string) {
  const module = await import(`./modules/${name}`);
  return module.default as () => void;
}

const run = async () => {
  const fn = await loadModule('featureA');
  fn();
};

This code dynamically imports a module by name and runs its default exported function.

Identify Repeating Operations

Identify the loops, recursion, array traversals that repeat.

• Primary operation: Dynamic import call to load a module.
• How many times: Once per requested module name.

How Execution Grows With Input

Each dynamic import loads one module. If you import more modules, the total time grows with the number of imports.

Input Size (n)	Approx. Operations
1	1 module load
10	10 module loads
100	100 module loads

Pattern observation: The time grows linearly as you import more modules dynamically.

Final Time Complexity

Time Complexity: O(n)

This means the loading time increases directly in proportion to the number of dynamic imports.

Common Mistake

[X] Wrong: "Dynamic imports load all modules at once, so time stays the same regardless of number."

[OK] Correct: Each dynamic import loads a separate module, so more imports mean more loading time.

Interview Connect

Understanding how dynamic imports affect loading time helps you write efficient code and explain module loading behavior clearly.

Self-Check

"What if we cached imported modules so repeated imports don't reload them? How would the time complexity change?"