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;

const list = [];
let num = 2;
rl.on("line", (line) => {
    list.push(line);
    if ((list.length == num)) {
        console.log(
            list[0]
                .toLowerCase()
                .split("")
                .filter((li) => li == list[1].toLowerCase()).length
        );
    }
});