JSON String Escaping

// Best practice: Use JSON.stringify
const obj = {
  name: 'John "The King"',
  path: 'C:\\Users\\John',
  message: 'Line 1\nLine 2\tTabbed'
};

const json = JSON.stringify(obj);
console.log(json);
// {"name":"John \"The King\"","path":"C:\\Users\\John",...}

// Pretty print
const prettyJson = JSON.stringify(obj, null, 2);

// Manual escape (rarely needed)
function escapeJsonString(str) {
  return str
    .replace(/\\/g, '\\\\')     // Backslash
    .replace(/"/g, '\\"')          // Quote
    .replace(/\n/g, '\\n')        // Newline
    .replace(/\r/g, '\\r')        // Carriage return
    .replace(/\t/g, '\\t')        // Tab
    .replace(/\b/g, '\\b')        // Backspace
    .replace(/\f/g, '\\f')        // Form feed
    .replace(/[\x00-\x1f]/g, c => { // Control chars
      return '\\u' + ('0000' + c.charCodeAt(0).toString(16)).slice(-4);
    });
}

// Unescape JSON string
function unescapeJsonString(str) {
  return str
    .replace(/\\"/g, '"')
    .replace(/\\\\/g, '\\')
    .replace(/\\n/g, '\n')
    .replace(/\\r/g, '\r')
    .replace(/\\t/g, '\t')
    .replace(/\\u([0-9a-fA-F]{4})/g, (match, hex) => {
      return String.fromCharCode(parseInt(hex, 16));
    });
}

// Parse with error handling
function safeJsonParse(str) {
  try {
    return JSON.parse(str);
  } catch (error) {
    console.error('Invalid JSON:', error.message);
    return null;
  }
}

// Stringify with circular reference handling
function safeJsonStringify(obj) {
  const seen = new WeakSet();
  return JSON.stringify(obj, (key, value) => {
    if (typeof value === 'object' && value !== null) {
      if (seen.has(value)) {
        return '[Circular]';
      }
      seen.add(value);
    }
    return value;
  });
}

import json

# Encode to JSON (handles escaping automatically)
data = {
    'name': 'John "The King"',
    'path': 'C:\\Users\\John',
    'message': 'Line 1\nLine 2\tTabbed'
}

json_str = json.dumps(data)
print(json_str)

# Pretty print
pretty_json = json.dumps(data, indent=2)

# Decode from JSON
parsed = json.loads(json_str)

# Custom JSON encoder for non-serializable types
from datetime import datetime

class DateTimeEncoder(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj, datetime):
            return obj.isoformat()
        return super().default(obj)

data_with_date = {'timestamp': datetime.now()}
json.dumps(data_with_date, cls=DateTimeEncoder)

# Handle encoding errors
json.dumps(data, ensure_ascii=False)  # Allow Unicode
json.dumps(data, ensure_ascii=True)   # Escape Unicode