fibfunc/src/fib5.js

/**
 * 
 * @param {for循环+解构赋值} n 
 * @returns 
 */

var fibonacci = function (n) {
    let n1 = 1; n2 = 1;
    for (let i = 2; i < n; i++) {
        [n1, n2] = [n2, n1 + n2]
    }
    return n2
}

module.exports = fibonacci