[ { "id": 1, "type": "single", "category": "HTML", "question": "以下哪个标签用于定义页面的主标题？", "options": ["A. ", "B.

", "C. ", "D. <header>"], "answer": "B", "explanation": "<h1> 标签定义 HTML 文档中最高级别的标题，<title> 定义浏览器标题栏文字。" }, { "id": 2, "type": "single", "category": "CSS", "question": "CSS 中，以下哪个属性用于改变文本颜色？", "options": ["A. font-color", "B. text-color", "C. color", "D. foreground"], "answer": "C", "explanation": "CSS 使用 color 属性来设置文本颜色。" }, { "id": 3, "type": "multi", "category": "JavaScript", "question": "以下哪些是 JavaScript 的原始数据类型？（多选）", "options": ["A. String", "B. Number", "C. Array", "D. Boolean", "E. Symbol"], "answer": "A,B,D,E", "explanation": "JavaScript 原始类型包括：String, Number, Boolean, Null, Undefined, Symbol, BigInt。Array 是对象类型。" }, { "id": 4, "type": "judge", "category": "HTML", "question": "HTML 中 <br> 标签需要闭合标签。</br> 才能正常工作。", "options": ["正确", "错误"], "answer": "错误", "explanation": "<br> 是自闭合标签（void element），不需要闭合标签。" }, { "id": 5, "type": "single", "category": "PHP", "question": "PHP 中获取数组长度的函数是？", "options": ["A. length()", "B. size()", "C. count()", "D. sizeof()"], "answer": "C", "explanation": "count() 是获取数组长度的推荐函数，sizeof() 是 count() 的别名。" }, { "id": 6, "type": "fill", "category": "CSS", "question": "CSS 中，使用 _______ 属性可以设置元素的外边距。", "answer": "margin", "explanation": "margin 属性用于设置元素的外边距（margin-top, margin-right, margin-bottom, margin-left）。" }, { "id": 7, "type": "judge", "category": "JavaScript", "question": "JavaScript 中 == 会比较值和类型，=== 只比较值。", "options": ["正确", "错误"], "answer": "错误", "explanation": "恰好相反：== 会进行类型转换后比较值，=== 严格比较值和类型。" }, { "id": 8, "type": "single", "category": "HTML", "question": "HTML5 中，用于播放视频的标签是？", "options": ["A. <movie>", "B. <video>", "C. <media>", "D. <player>"], "answer": "B", "explanation": "HTML5 使用 <video> 标签嵌入视频内容。" }, { "id": 9, "type": "multi", "category": "CSS", "question": "以下哪些是 CSS3 新增的选择器？（多选）", "options": ["A. :nth-child()", "B. ::before", "C. :hover", "D. :not()", "E. ::placeholder"], "answer": "A,B,D,E", "explanation": ":hover 在 CSS2 就已存在，其余都是 CSS3 新增的选择器。" }, { "id": 10, "type": "fill", "category": "JavaScript", "question": "JavaScript 中声明常量使用的关键字是 _______。", "answer": "const", "explanation": "const 用于声明块级作用域的常量，一旦赋值不能重新赋值。" }, { "id": 11, "type": "single", "category": "PHP", "question": "PHP 中用于连接字符串的运算符是？", "options": ["A. +", "B. &", "C. . ", "D. ++"], "answer": "C", "explanation": "PHP 使用点号（.）来连接（拼接）字符串。" }, { "id": 12, "type": "judge", "category": "CSS", "question": "CSS 中 display: none 会将元素从文档流中完全移除。", "options": ["正确", "错误"], "answer": "正确", "explanation": "display: none 使元素完全不渲染，不占据空间。visibility: hidden 才是隐藏但保留空间。" } ]