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js实现Scanner

2026-03-15 07:29:30JavaScript

js实现Scanner

JavaScript 实现类似 Java Scanner 的功能

JavaScript 没有内置的 Scanner 类，但可以通过以下方式模拟类似功能：

js实现Scanner

使用浏览器控制台输入

function Scanner() {
  this.nextLine = function() {
    return prompt("Enter input:");
  };
  this.nextInt = function() {
    return parseInt(prompt("Enter integer:"));
  };
  this.nextFloat = function() {
    return parseFloat(prompt("Enter float:"));
  };
}

const scanner = new Scanner();
const name = scanner.nextLine();
const age = scanner.nextInt();

使用 Node.js 的 readline 模块

const readline = require('readline');

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

  this.nextLine = function() {
    return new Promise(resolve => {
      rl.question('', answer => {
        resolve(answer);
      });
    });
  };

  this.nextInt = async function() {
    const input = await this.nextLine();
    return parseInt(input);
  };

  this.close = function() {
    rl.close();
  };
}

(async function() {
  const scanner = new Scanner();
  console.log("Enter your name:");
  const name = await scanner.nextLine();
  console.log("Enter your age:");
  const age = await scanner.nextInt();
  scanner.close();
})();

处理字符串输入

如果需要从字符串中解析数据：

function Scanner(input) {
  this.input = input.trim().split(/\s+/);
  this.index = 0;

  this.hasNext = function() {
    return this.index < this.input.length;
  };

  this.next = function() {
    return this.input[this.index++];
  };

  this.nextInt = function() {
    return parseInt(this.next());
  };

  this.nextFloat = function() {
    return parseFloat(this.next());
  };
}

const scanner = new Scanner("John 25 175.5");
const name = scanner.next();
const age = scanner.nextInt();
const height = scanner.nextFloat();