如何实现两个非常大的数字(已经超出了Number范围)的加法运算。 注意由于这两个已经超过了Num

function bigNumberSum(a, b) { // 123456789 // 000009876

// padding let cur = 0; while (cur < a.length || cur < b.length) { if (!a[cur]) { a = "0" + a; } else if (!b[cur]) { b = "0" + b; } cur++; }

let carried = 0; const res = [];

for (let i = a.length - 1; i > -1; i--) { const sum = carried + +a[i] + +b[i]; if (sum > 9) { carried = 1; } else { carried = 0; } res[i] = sum % 10; } if (carried === 1) { res.unshift(1); }

return res.join(""); }