<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>Document</title> <script src="./lib/vue-2.4.0.js"></script> </head> <body> <div id="app"> <input type="text" v-model="n1"> <select v-model="opt"> <option value="+">+</option> <option value="-">-</option> <option value="*">*</option> <option value="/">/</option> </select> <input type="text" v-model="n2"> <input type="button" value="=" @click="calc"> <input type="text" v-model="result"> </div> <script> // 创建 Vue 实例，得到 ViewModel var vm = new Vue({ el: '#app', data: { n1: 0, n2: 0, result: 0, opt: '+' }, methods: { calc() { // 计算器算数的方法 // 逻辑： /* switch (this.opt) { case '+': this.result = parseInt(this.n1) + parseInt(this.n2) break; case '-': this.result = parseInt(this.n1) - parseInt(this.n2) break; case '*': this.result = parseInt(this.n1) * parseInt(this.n2) break; case '/': this.result = parseInt(this.n1) / parseInt(this.n2) break; } */ // 注意：这是投机取巧的方式，正式开发中，尽量少用 var codeStr = 'parseInt(this.n1) ' + this.opt + ' parseInt(this.n2)' this.result = eval(codeStr) } } }); </script> </body> </html>