3b:["$","hr","28",{"children":"$undefined"}] 3c:["$","h2","30",{"children":"keyof Constraint"}] 3d:["$","pre","32",{"children":["$","code",null,{"className":"language-typescript","children":["// Get property value with type safety\nfunction getProperty(obj: T, key: K): T[K] {\n return obj[key];\n}\n\nconst user = { name: 'Alice', age: 30 };\n\nconst name = getProperty(user, 'name'); // type: string\nconst age = getProperty(user, 'age'); // type: number\ngetProperty(user, 'email'); // ",["$","svg","1",{"ref":"$undefined","xmlns":"http://www.w3.org/2000/svg","width":24,"height":24,"viewBox":"0 0 24 24","fill":"none","stroke":"currentColor","strokeWidth":2,"strokeLinecap":"round","strokeLinejoin":"round","className":"lucide lucide-x inline-block w-5 h-5 text-red-500 align-text-bottom mr-1","aria-hidden":"true","children":[["$","path","1bl5f8",{"d":"M18 6 6 18"}],["$","path","d8bk6v",{"d":"m6 6 12 12"}],"$undefined"]}]," Error: 'email' not in User\n"]}]}] 3e:["$","hr","34",{"children":"$undefined"}] 3f:["$","h2","36",{"children":"Generic Interfaces"}] 40:["$","pre","38",{"children":["$","code",null,{"className":"language-typescript","children":"// Generic container\ninterface Box {\n value: T;\n getValue(): T;\n}\n\nconst numberBox: Box = {\n value: 42,\n getValue() { return this.value; }\n};\n\n// Generic API response\ninterface ApiResponse {\n data: T;\n status: number;\n message: string;\n}\n\ninterface User {\n id: number;\n name: string;\n}\n\nconst response: ApiResponse = {\n data: { id: 1, name: 'Alice' },\n status: 200,\n message: 'Success'\n};\n"}]}] 41:["$","hr","40",{"children":"$undefined"}] 42:["$","h2","42",{"children":"Generic Classes"}] 43:["$","pre","44",{"children":["$","code",null,{"className":"language-typescript","children":"class Stack {\n private items: T[] = [];\n\n push(item: T): void {\n this.items.push(item);\n }\n\n pop(): T | undefined {\n return this.items.pop();\n }\n\n peek(): T | undefined {\n return this.items[this.items.length - 1];\n }\n}\n\nconst numberStack = new Stack();\nnumberStack.push(1);\nnumberStack.push(2);\nconst top = numberStack.pop(); // type: number | undefined\n\nconst stringStack = new Stack();\nstringStack.push('hello');\n"}]}] 44:["$","hr","46",{"children":"$undefined"}] 45:["$","h2","48",{"children":"Default Type Parameters"}] 46:["$","pre","50",{"children":["$","code",null,{"className":"language-typescript","children":"// Default type if not specified\ninterface Container {\n value: T;\n}\n\nconst c1: Container = { value: 'hello' }; // T is string\nconst c2: Container = { value: 42 }; // T is number\n\n// Function with default\nfunction createArray(length: number, value: T): T[] {\n return Array(length).fill(value);\n}\n"}]}] 47:["$","hr","52",{"children":"$undefined"}] 48:["$","h2","54",{"children":"Practical Patterns"}] 49:["$","h3","56",{"children":"Generic Factory"}] 4a:["$","pre","58",{"children":["$","code",null,{"className":"language-typescript","children":"function createInstance(ctor: new () => T): T {\n return new ctor();\n}\n\nclass User {\n name = 'Default';\n}\n\nconst user = createInstance(User); // type: User\n"}]}] 4b:["$","h3","60",{"children":"Generic with Multiple Constraints"}] 4c:["$","pre","62",{"children":["$","code",null,{"className":"language-typescript","children":"interface HasId {\n id: number;\n}\n\ninterface HasName {\n name: string;\n}\n\nfunction process(item: T): string {\n return `${item.id}: ${item.name}`;\n}\n"}]}] 4d:["$","hr","64",{"children":"$undefined"}] 4e:["$","h2","66",{"children":"Common Mistakes"}]