Fibonacci

fibonacci.ts

function fibonacci(len) {
    const arr = [];

    ////
    // Moved the conditionals out of the loop
    if (len >= 1) {
        arr.push(0);
    }

    if (len >= 2) {
        arr.push(1);
    }
    ////

    for (let i = 2; i < len; i++) {
        arr.push(arr[i - 1] + arr[i - 2]);
    }

    return arr;
}

const result = fibonacci(5);
console.log(result);