js使用递归方法//输入斐波那契数列的项数num,求前num项的和 //示例：输入5，输出结果“斐波那契数列的前5项之和为12”

function fibonacci(num) {
if (num <= 1) {
return num;
} else {
return fibonacci(num - 1) + fibonacci(num - 2);
}
}

function fibonacciSum(num) {
let sum = 0;
for (let i = 0; i < num; i++) {
sum += fibonacci(i);
}
return sum;
}

const num = 5;
const sum = fibonacciSum(num);
console.log(`斐波那契数列的前${num}项之和为${sum}`); // 输出：斐波那契数列的前5项之和为12