题解 | #计算某字符出现次数#

const rl = require('readline').createInterface({
    input: process.stdin,
    output: process.stdout
});

const inputs = [];
rl.on('line', (line) => {
    inputs.push(line.trim());
}).on('close', () => {
    // 不区分大小写，那就全部转成小写再匹配
    let str = inputs[0].toLowerCase();
    const key = inputs[1].toLowerCase();
    let times = 0;
    for(let i = 0; i < str.length; i++) {
        if(str[i] === key) {
            times += 1;
        }
    }
    console.log(times);
})

这道题仅仅查找单个字符 视情况而定用哈希吧，就单解题的情景下没必要