TypeScript - Iterative Fibonacci sequence / number algorithm

const calculateValue = (input: number) => {

  if (input < 1) {

    return 0;

  }

  let a = 0;

  let b = 1;

  for (let i = 1; i < input; ++i) {

    const c = a + b;

    a = b;

    b = c;

  }

  return b;

};

​

// Example:

​

for (let n = 0; n < 10; ++n) {

  console.log('f(' + n + ')=' + calculateValue(n));

}

f(0)=0

f(1)=1

f(2)=1

f(3)=2

f(4)=3

f(5)=5

f(6)=8

f(7)=13

f(8)=21

f(9)=34