Create Hello World Function - Problem
In JavaScript, closures are one of the most fundamental concepts that every developer must master. This problem introduces you to the world of higher-order functions - functions that return other functions.
Your task is to write a function called createHelloWorld that doesn't take any parameters, but returns a new function. This returned function should always output the string "Hello World" when called, regardless of what arguments are passed to it.
Key Learning Goals:
- Understanding closures and function factories
- Learning how functions can return other functions
- Grasping the concept of consistent behavior in returned functions
This is a perfect introduction to functional programming concepts that you'll encounter in more complex problems involving counters, memoization, and function composition.
Input & Output
example_1.js — Basic Usage
$
Input:
const f = createHelloWorld();
f();
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Output:
"Hello World"
💡 Note:
The function is created and called with no arguments, returning the expected string.
example_2.js — With Arguments
$
Input:
const f = createHelloWorld();
f({}, null, 42);
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Output:
"Hello World"
💡 Note:
Even when arguments are passed, the function ignores them and returns 'Hello World'.
example_3.js — Multiple Calls
$
Input:
const f = createHelloWorld();
f();
f('test', 123);
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Output:
"Hello World"
"Hello World"
💡 Note:
Each call to the returned function consistently produces the same output regardless of arguments.
Constraints
- The returned function can be called with any number of arguments
- The returned function should always return the exact string "Hello World"
- Arguments passed to the returned function should be ignored
Visualization
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Understanding the Visualization
1
Factory Setup
createHelloWorld() sets up the card printing machine
2
Machine Created
Returns a function that represents the card printer
3
Card Production
Every time you use the printer, it produces 'Hello World' cards
Key Takeaway
🎯 Key Insight: Closures allow functions to return other functions, creating powerful patterns for consistent behavior and encapsulation.
💡
Explanation
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