ASCII Tables in Computer Science and Web Development

"Hello, Web Developer!"

function decodeASCII(codes) {
    return codes.map(code => String.fromCharCode(code)).join('');
}

const message = [72, 101, 108, 108, 111, 44, 32, 87, 101, 98, 32, 68, 101, 118, 101, 108, 111, 112, 101, 114, 33];
console.log(decodeASCII(message)); // "Hello, Web Developer!"

<!-- HTML -->
<form id="encoder-form">
    <label for="input-text">Enter text to encode:</label>
    <input type="text" id="input-text" name="text" />
    <button type="submit">Encode</button>
</form>

<div id="results">
    <div id="url-encoded"></div>
    <table id="ascii-table">
        <thead>
            <tr>
                <th>Character</th>
                <th>ASCII Code</th>
                <th>URL Encoded</th>
            </tr>
        </thead>
        <tbody></tbody>
    </table>
</div>

<!-- JavaScript -->
<script>
document.getElementById('encoder-form').addEventListener('submit', function(e) {
    e.preventDefault();
    
    const text = document.getElementById('input-text').value;
    const encoded = encodeURIComponent(text);
    
    // Display URL encoded version
    document.getElementById('url-encoded').textContent = `URL Encoded: ${encoded}`;
    
    // Build ASCII table
    const tbody = document.querySelector('#ascii-table tbody');
    tbody.innerHTML = '';
    
    for (let i = 0; i < text.length; i++) {
        const char = text[i];
        const code = char.charCodeAt(0);
        const urlChar = encodeURIComponent(char);
        
        const row = document.createElement('tr');
        row.innerHTML = `
            <td>${char === ' ' ? '(space)' : char}</td>
            <td>${code}</td>
            <td>${urlChar}</td>
        `;
        tbody.appendChild(row);
    }
});
</script>

function convertCase(text) {
    let upperResult = '';
    let lowerResult = '';
    
    for (let i = 0; i < text.length; i++) {
        const char = text[i];
        const code = char.charCodeAt(0);
        
        // Convert to uppercase (if lowercase letter)
        if (code >= 97 && code <= 122) {
            upperResult += String.fromCharCode(code - 32);
        } else {
            upperResult += char;
        }
        
        // Convert to lowercase (if uppercase letter)
        if (code >= 65 && code <= 90) {
            lowerResult += String.fromCharCode(code + 32);
        } else {
            lowerResult += char;
        }
    }
    
    return {
        original: text,
        upper: upperResult,
        lower: lowerResult
    };
}

// Test the function
const result = convertCase("Hello, World! 123");
console.log(result.upper); // "HELLO, WORLD! 123"
console.log(result.lower); // "hello, world! 123"