Category: JavaScript

JavaScript　パスワード生成

配列からランダムな引数をとるには、Math.floor(Math.random() * xxx.length)のように書きます。

<!DOCTYPE html>
<html lang="ja">
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Password Generator</title>
    <link rel="stylesheet" href="styles.css">
    <style>
      body {
        background: #e0e0e0;
        text-align: center;
        font-family: 'Courier New', sans-serif;
      }
      .container {
        width: 320px;
        margin: 30px auto;
      }
      input[type="text"]{
        width: 300px;
        padding: 7px;
        border-radius: 3px;
        font-size: 24px;
        font-family: 'Courier New', sans-serif;
        text-align: center;
      }
      #btn {
        color: #fff;
        background: #00aaff;
        padding: 7px;
        border-radius: 5px;
        box-shadow: 0 4px 0 #0088cc;
        cursor: pointer;
      }
      #btn:hover {
        opacity: 0.8;
      }
      fieldset {
        margin-top: 40px;
        border: 1px dashed #aaa;
        border-radius: 5px;
        text-align: left;
      }
      legend {
        font-weight: bold;
        padding: 0 10px;
      }
      fieldset p {
        text-align: center;
      }
    </style>
  </head>
  <body>
      <div class="container">
        <p><input type="text" id="result"></p>
        <p><div id="btn">Generate Password</div></p>
        <fieldset>
          <legend>Options</legend>
          <p>Length(<span id="label">8</span>): <input type="range" id="slider" value="8" min="4" max="20"</p>
          <p>
            Numbers?: <input type="checkbox" id="numbers">
            Symbols?: <input type="checkbox" id="symbols">
          </p>
        </fieldset>
        </div>
      <script>

          (function(){
              'use strict'

              var slider = document.getElementById('slider');
              var label = document.getElementById('label');
              var btn = document.getElementById('btn');
              var result = document.getElementById('result');
              var numbers = document.getElementById('numbers');
              var symbols = document.getElementById('symbols');

              function getPassword(){
                var seed_letters = 'abcdefghijklmnopqrstuvwxyz';
                var seed_numbers = '0123456789';
                var seed_symbols = '!#$%&()';
                var seed;
                var len = slider.value;
                var pwd = '';

                seed = seed_letters + seed_letters.toUpperCase();
                if (numbers.checked === true){
                  seed += seed_numbers;
                }
                 if (symbols.checked === true){
                  seed += seed_symbols;
                }

               // for (var i = 0; i < len; i++){
               //   pwd += seed&#91;Math.floor(Math.random() * seed.length)&#93;;
               // }
                while(len--){
                  pwd += seed&#91;Math.floor(Math.random() * seed.length)&#93;;
                }

                result.value = pwd;
              }
              slider.addEventListener('change', function(){
                  label.innerHTML = this.value;
              });
              btn.addEventListener('click', function(){
                  getPassword();
                  // result.value = 'asdfasdf';
              });
              result.addEventListener('click', function(){
                  this.select();
              });

              getPassword();



          })();

      </script>
  </body>
</html>

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JavaScript 秒数当てゲーム

秒数当てゲームもストップウォッチのように、(Date.now()- startTime) / 1000 と記載していきます。

<!DOCTYPE html>
<html lang="ja">
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>stop at 00:05!</title>
    <link rel="stylesheet" href="styles.css">
    <style>
    body {
      background: #e0e0e0;
      text-align: center;
      font-size: 16px;
      font-family: Arial, san-serif;
    }
    #result {
      font-weight: bold;
      font-size: 32px;
      margin: 60px auto;
      color: #00aaff;
      text-shadow: 0 1px 0 rgba(255, 255, 255, 0.5);
    }
    #btn {
      margin: 0 auto;
      width: 200px;
      padding: 7px;
      color: #fff;
      border-radius: 5px;
      background: #00aaff;
      box-shadow: 0 4px 0 #0088cc;
      cursor: pointer;
    }
    #btn:hover {
      opacity: 0.8;
    }
    </style>
  </head>
  <body>
      <div id="result"></div>
      <div id="btn">START</div>
      <script>
      (function(){
        'use strict';
        var isStarted = false;
        var startTime;
        var diff;
        var msg = 'Stop at 00:05!'

        var result = document.getElementById('result');
        var btn = document.getElementById('btn');

        result.innerHTML = msg;

        btn.addEventListener('click', function(){
            if (!isStarted){
              isStarted = true;
              this.innerHTML = 'STOP';
              startTime = Date.now();
              result.innerHTML = msg;
            } else {
              isStarted = false;
              this.innerHTML = 'START';
              diff = (Date.now()- startTime) / 1000 -5;
              if (diff >= -0.1 && diff <= 0.1){
                result.innerHTML = 'Perfect!';
              } else if (diff > 0){
                result.innerHTML = 'You are ' + diff.toFixed(2) + 'seconds late!';
              } else {
                result.innerHTML = 'You are ' + Math.abs(diff).toFixed(2) + 'seconds first!';
              }
            }
        });
      })();
      </script>
  </body>
</html>

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JavaScript ストップウォッチ

ストップウォッチは、Date関数を上手く活用して、クリックしたタイミングの差分を表示します。

<!DOCTYPE html>
<html lang="ja">
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>ストップウォッチ</title>
    <link rel="stylesheet" href="styles.css">
    <style>
    body {
      background: #e0e0e0;
      font-family: Arial, sans-serif;
      text-align: center;
    }
    #timerText{
      color: #00aaff;
      font-size: 128px;
      margin: 40px auto;
      text-shadow: 0 1px 0 rgba(255, 255, 255, 0.5);
    }
    .btn{
      display: inline-block;
      width: 100px;
      padding: 7px;
      border-radius: 5px;
      box-shadow: 0 4px 0 #0088cc;
      color: #fff;
      background: #00aaff;
      cursor: pointer;
    }
    .btn + .btn {
      margin-left:10px;
    }
    .btn.active {
      opacity: 1.0;
    }
    .btn.inactive {
      opacity: 0.5;
    }
    </style>
  </head>
  <body>
      <div id="timerText">0.00</div>
      <div id="start">START</div>
      <div id="stop">STOP</div>
      <div id="reset">RESET</div>
      <script>
        (function(){
          'use strict';

          var startTime;
          var timerId;
          var elapsedTime = 0;
          var isRunning = false;

          var startButton = document.getElementById('start');
          var stopButton = document.getElementById('stop');
          var resetButton = document.getElementById('reset');
          var timerText = document.getElementById('timerText');

          function setButtonState(start, stop, reset){
            startButton.className = start ? 'btn active' : 'btn inactive';
            stopButton.className = stop ? 'btn active' : 'btn inactive';
            resetButton.className = reset ? 'btn active' : 'btn inactive';
          }

          setButtonState(true, false, false);

          startButton.addEventListener('click', function(){
            if (isRunning) return;
            isRunning = true;
                startTime = Date.now();
                updateTimerText();
                setButtonState(false, true, false);
          });

          stopButton.addEventListener('click', function(){
            if (!isRunning) return;
            isRunning = false;
            elapsedTime += Date.now()- startTime;
            clearTimeout(timerId);
            setButtonState(true, false, true);
          });

          resetButton.addEventListener('click', function(){
            if (isRunning) return;
            timerText.innerHTML = '0.00';
            elapsedTime = 0;
            setButtonState(true, false, false);
          });

          function updateTimerText(){
            timerId = setTimeout(function(){
                var t = Date.now() - startTime + elapsedTime;
                timerText.innerHTML = (t / 1000).toFixed(2);
                updateTimerText();
            }, 10);
          }

        })();
      </script>
  </body>
</html>

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Javascript おみくじ

<!DOCTYPE html>
<html lang="ja">
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>おみくじ</title>
    <link rel="stylesheet" href="styles.css">
    <style>
      body {
        background : #e0e0e0;
        text-align: center;
        font-size: 16px;
        color: #fff;
        font-family: Arial, sans-serif;
      }
      #result {
        margin: 30px auto;
        width: 180px;
        height: 180px;
        border-radius: 50%;
        line-height: 180px;
        font-size: 48px;
        font-weight: bold;
        background: #f44336;
        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
      }
      #btn {
        margin: 0 auto;
        width: 200px;
        padding: 5px;
        border-radius: 5px;
        background: #00aaff;
        box-shadow: 0 4px 0 #0088cc;
        cursor: pointer;
      }
      #btn:hover{
        opacity: 0.8;
      }
      #btn.pushed{
        margin-top: 32px;
        box-shadow: 0 2px 0 #0088cc;
      }
    </style>
  </head>
  <body>
      <div id="result">?</div>
      <div id="btn">あなたの運勢は？</div>
      <script>
        (function(){
          "use strict";
          document.getElementById('btn').addEventListener('click', function(){
            var results = ['大吉','中吉','小吉','凶'];
            var result = Math.floor(Math.random() * results.length);
            document.getElementById('result').innerHTML = results[result];
          });
          document.getElementById('btn').addEventListener('mousedown', function(){
            this.className = 'pushed';
          });
          document.getElementById('btn').addEventListener('mouseup', function(){
            this.className = '';
          });
        })();
      </script>
  </body>
</html>

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JavaScript 基礎

JavaScriptのドキュメントはMDNのサイトでよく参照することができます。
MDN JavaScript

即時関数：直ぐに実行されます。

<script>
      　(function(name){
        console.log("hello" + name);
      })("tom");
      </script>

      <script>
      (function()){
        var x = 10;
        y = 20;
        console.log(x + y);
      }();
      </script>

setInterval

var i = 0;
      function show(){
        console.log(i++)
      }
      setInterval(function(){
        show();
      }, 1000);

setTimeout

var i = 0;
      function show(){
        console.log(i++);
        setTimeout(function(){
          show();
        }, 1000);
      }show();

オブジェクト

var user = {
        email: "yamada@gmail.com",
        score: 80
      };
      console.log(user.email)

オブジェクト2

var user = {
        email: "yamada@gmail.com",
        score: 80,
        greet: function(name){
          console.log("hello, " + name);
        }
      };
      user.greet("sato");

Arrayオブジェクト

var a = new Array(100, 300, 200);
      console.log(a.length);

Math

      console.log(Math.PI);
      console.log(Math.ceil(5.3));
      console.log(Math.floor(5.3));
      console.log(Math.round(5.3));

三項演算子
a = (条件) ? b : c;

よく使うもの

console.log(window.outerHeight);
window.location.href = "http://google.com"
document(DOM)
var e = document.getElementById('msg');
      e.textContent = 'Hello';
      e.style.color = 'red';