Dynamic Imports in JavaScript Modules

Dynamic Imports:

Write a JavaScript programme that uses dynamic imports to load a module and invoke its function asynchronously.

Solution-1: Using import() with Async Function

JavaScript Code:

File: mathOperations.js

// mathOperations.js
// Exporting a function from mathOperations.js
export const multiply = (a, b) => a * b; // Multiplies two numbers

File: main.js

//main.js
// Async function to dynamically import and use the module
async function loadAndMultiply(a, b) {
  // Dynamically importing the module
  const mathModule = await import('./mathOperations.js');
  
  // Using the imported function
  console.log(mathModule.multiply(a, b)); // Logs the result of multiplication
}

// Calling the function
loadAndMultiply(4, 5); // Logs 20

Output:

20

Explanation:

• The multiply function is exported from mathOperations.js.
• In main.js, an async function loadAndMultiply is defined to dynamically import the module.
• The import() function is used to load the module when needed, ensuring the code is split into chunks and loaded on demand.
• The multiply function from the dynamically imported module is then invoked to calculate the product.

Solution-2: Using import() Inside a Non-Async Function

JavaScript Code:

File: mathOperations.js

// mathOperations.js
// Exporting a function from mathOperations.js
export const multiply = (a, b) => a * b; // Multiplies two numbers

File: main.js

//main.js
// Using dynamic import inside a regular function
function loadAndDivide(a, b) {
  import('./mathOperations.js')
    .then((mathModule) => {
      console.log(mathModule.multiply(a, b)); // Logs the result of multiplication
    })
    .catch((error) => {
      console.error('Error loading the module:', error); // Handles import errors
    });
}

// Calling the function
loadAndDivide(6, 3); // Logs 18

Output:

18

Explanation:

• The multiply function is exported from mathOperations.js.
• In main.js, a regular function loadAndDivide is defined.
• The import() function is used with a .then() chain to dynamically load the module.
• The multiply function is called after the module is successfully loaded, and errors are handled using .catch().

For more Practice: Solve these Related Problems:

• Write a JavaScript program that dynamically imports a module when a button is clicked and then calls a function from the module.
• Write a JavaScript program that uses dynamic import() to load a configuration file asynchronously and applies its settings.
• Write a JavaScript program that dynamically imports a module based on user input and logs the module’s exported functions.
• Write a JavaScript program that loads a module dynamically and handles any errors during the import process gracefully.

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• JavaScript Modules and Imports/Exports Exercises Home ↩
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