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JavaScript Getting Started With ES2015 Create Functions Using Arrow Syntax Concise Arrow Function Syntax

tomd
tomd
16,701 Points
Posted by tomd
tomd
16,701 Points

Updating old code, arrow function doesn't work

I don't understand why this doesn't work. If you call functions in the same way then it should work.

var upper = 10;
var randomNumber = getRandomNumber(upper);
var guess;
var attempts = 0;

const getRandomNumber = upper => Math.floor(Math.random() * upper) + 1;

while (guess !== randomNumber){
  guess = getRandomNumber(upper);
  attempts += 1;
}
document.write(getRandomNumber(upper));
document.write("The number was " + randomNumber + "<br />");
document.write(" It took the computer " + attempts + " attempts");

1 Answer

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

You should be aware that an arrow function isn't always a suitable replacement for a conventional function, see the MDN page for details.

But what's causing the trouble here is that an assignment is not hoisted like a conventional function definition would be. So the assignment of "getRandomNumber" needs to be done before you call it to create "randomNumber".

tomd
tomd
16,701 Points
tomd
tomd
16,701 Points

Oh okay, i understand now. Thank you!