题解 | #截取字符串#

const readline = require('readline');

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

const inputs = [];

rl.on('line', (line) => {
    inputs.push(line.trim());
}).on('close', () => {
    const str = inputs[0];
    const k = inputs[1];
    let res = '';
    for(let i = 0; i < k; i++) {
        res += str[i];
    }
    console.log(res);
})

处理多行输入

实现类似String.prototype.slice(start, end)截取字符串的功能