61 lines
1.0 KiB
JavaScript
61 lines
1.0 KiB
JavaScript
// 输出到控制台
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console.log("Hello, World!");
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// 变量声明
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var name = "Alice"; // 不推荐，因为它有作用域问题
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let age = 25; // 推荐
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const pi = 3.14159; // 用于常量
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// 数据类型
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let number = 42; // 数字
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let text = "Hello"; // 字符串
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let isTrue = true; // 布尔值
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let items = [1, 2, 3]; // 数组
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let person = { name: "John", age: 30 }; // 对象
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// 基本运算
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let sum = 10 + 5; // 加法
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let difference = 10 - 5; // 减法
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let product = 10 * 5; // 乘法
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let quotient = 10 / 5; // 除法
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let a = 0.1;
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let b = 0.2;
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let c = a + b; // 浮点加法
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// 条件语句
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let abc = 10;
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if (abc > 0) {
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console.log("abc is positive.");
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} else if (abc < 0) {
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console.log("abc is negative.");
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} else {
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console.log("abc is zero.");
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}
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console.log('');
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// for 循环
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for (let i = 0; i < 5; i++) {
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console.log(i);
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}
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console.log('')
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// while 循环
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let i = 0;
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while (i < 5) {
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console.log(i);
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i++;
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}
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console.log('');
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// 函数定义和调用
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function greet(name) {
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return "Hello, " + name;
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}
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console.log(greet("Guan")); |