题解 | 计算某字符出现次数

const rl = require("readline").createInterface({ input: process.stdin });
var iter = rl[Symbol.asyncIterator]();
const readline = async () => (await iter.next()).value;

void (async function () {
    // Write your code here
    const str = await readline();
    const char = await readline();
    const reg = new RegExp(char, "ig");
    console.log([...str.matchAll(reg)].length);
})();