// 1. Basic Methods of Checking for Double Quote

// Method 1: Direct Comparison
function isDoubleQuote_DirectCompare(char) {
    return char === '"';
}

// Method 2: Character Code Comparison
function isDoubleQuote_CharCode(char) {
    return char.charCodeAt(0) === 34;
}

// Method 3: Unicode Escape Sequence
function isDoubleQuote_Unicode(char) {
    return char === '\u0022';
}

// 2. Advanced Checking Techniques

// Method 4: Regex-based Check
function isDoubleQuote_Regex(char) {
    return /^"$/.test(char);
}

// Method 5: Type-Safe Checking with Additional Validation
function isDoubleQuote_TypeSafe(char) {
    // Ensures input is a string and exactly one character
    return typeof char === 'string' && 
           char.length === 1 && 
           char === '"';
}

// 3. Performance-Optimized Checking
function isDoubleQuote_Performance(char) {
    // Fastest method for large-scale operations
    return char === '"' 
        || char.charCodeAt(0) === 34;
}

// 4. Comprehensive Quote Detection Utility
class QuoteDetector {
    constructor() {
        // Caching for performance
        this.doubleQuoteCode = '"'.charCodeAt(0);
        this.singleQuoteCode = "'".charCodeAt(0);
    }

    // Detect any type of quote
    isQuote(char) {
        if (!char || typeof char !== 'string' || char.length !== 1) {
            return false;
        }
        
        const charCode = char.charCodeAt(0);
        return charCode === this.doubleQuoteCode || 
               charCode === this.singleQuoteCode;
    }

    // Specifically check for double quote
    isDoubleQuote(char) {
        return this.isQuote(char) && char === '"';
    }
}

// Example Usage
function demonstrateQuoteChecking() {
    const detector = new QuoteDetector();

    const testCases = ['"', "'", 'a', ''];
    
    console.log("Quote Detection Results:");
    testCases.forEach(char => {
        console.log(`Character '${char}':
            Direct Compare: ${isDoubleQuote_DirectCompare(char)}
            Char Code: ${isDoubleQuote_CharCode(char)}
            Unicode: ${isDoubleQuote_Unicode(char)}
            Regex: ${isDoubleQuote_Regex(char)}
            Type-Safe: ${isDoubleQuote_TypeSafe(char)}
            Performance Check: ${isDoubleQuote_Performance(char)}
            Detector Class: ${detector.isDoubleQuote(char)}
        `);
    });
}

// Run the demonstration
demonstrateQuoteChecking();

// Bonus: Edge Case Handling
function robustDoubleQuoteCheck(input) {
    // Handles various input types and edge cases
    if (input === null || input === undefined) return false;
    
    // Convert to string if not already a string
    const str = String(input);
    
    // Check for single character or escaped quote scenarios
    return str === '"' || 
           str === '\\"' || 
           str.charCodeAt(0) === 34;
}

// Practical Example: String Sanitization
function sanitizeString(str) {
    return str
        .split('')
        .filter(char => !isDoubleQuote_TypeSafe(char))
        .join('');
}

// Export for module usage
module.exports = {
    isDoubleQuote_DirectCompare,
    isDoubleQuote_CharCode,
    isDoubleQuote_Unicode,
    isDoubleQuote_Regex,
    isDoubleQuote_TypeSafe,
    isDoubleQuote_Performance,
    QuoteDetector,
    robustDoubleQuoteCheck,
    sanitizeString
};