"title": Title,
    "chapters": {
        "13c": {
            "words": 123,
            "spaces": 321
        },
        "15d": {
            "words": 123,
            "spaces": 321
        },
        "38h": {
            "words": 123,
            "spaces": 321
        }
    }

if(book.chapters.13c){
     console.log(book.chapters.13c);
}

Uncaught SyntaxError: Unexpected token ILLEGAL