Comprehensive and Detailed Explanation From Exact Extract JavaScript Knowledge:
Currently:
sayHello expects a value name and prints it.
world is a function that returns 'World'.
sayHello(world); passes the function object itself, not the result of calling it.
So name inside sayHello is a function, not the string "World".
To keep the call sayHello(world) yet get "World", sayHello must call the function parameter:
const sayHello = (name) => {
console.log('Hello', name());
};
Now:
sayHello(world) passes the function.
Inside sayHello, name() calls world(), which returns "World".
The console logs "Hello World".
Why the others are wrong:
B: Changing line 7 to }(); would attempt to IIFE the function definition and break the declaration.
C: sayHello(world)() would try to call the return value of sayHello, which is undefined, causing an error.
D: Changing world to a function declaration does not change the fact that it is passed as a function reference; sayHello still prints the function object, not 'World'.
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