roman01la/recursion-exercises

Recursion exercises in JavaScript

Practice recursion in JavaScript

What is recursion? When a function calls itself.

Take a look at this repeat function which yields a string of strings repeated specified number of times. Recursive function definition has a base or terminating case (without recurring) and recursive case.

function repeat(num, char) {

  // recursive case
  if (num - 1 > 0) {
    return char + repeat(num - 1, char);
  }
  // base case
  else {
    return char;
  }
}

repeat(3, 'Hey'); // 'HeyHeyHey'

Take a look at the test.js file in each directory to see what needs to be implemented, write an index.js as the solution file.

• Run all tests from the root: npm test
• Run a single test from the directory: npm test
• Run a single test in TDD mode from the directory: npm run tdd

recursion-exercises's Issues

code not working as expected

why this code doesn't work on page, while working in the dev console @ the same time?

function sum () {
  return (function sum_iter (arr, a) {
    var a=a||0;
    if (!arr.length)
      return a;
    a+=arr.pop();
    return sum_iter(arr, a)
  })([].splice.call(arguments,0))
}

Arrow functions do not seem to work

@roman01la...

For the "Sum" exercise, the following is accepted...

function sum(first, ...rest) {
    return first + (rest.length === 0 ? 0 : sum(...rest));
}

But otherwise identical code using an arrow function is rejected with a "Not recursive!" error...

const sum = (first, ...rest) => {
    return first + (rest.length === 0 ? 0 : sum(...rest));
}

My preferred, but also rejected, solution was simply...

const sum = (first, ...rest) => 
    first + (rest.length === 0 ? 0 : sum(...rest));

I am quite impressed with the interactive exercise format. I think I might nick a bit of your code.

Kind regards,

Stephen

fibonacci sequence

The fibonacci sequence of 5 should be [0,1,1,2,3,4,5]
https://www.mathsisfun.com/numbers/fibonacci-sequence.html

I'm trying to add my code as below but it's being rejected by the test
function fibonacci(num){
if (num === 0){
return [0];
}else if(num === 1){
return [0,1]
}else{
let list = fibonacci(num-1);
list.push(list[num-1] + list[num-2]);
return list;
}
}