一：打开WebStorm工具
1： 创建一个文件Lesson01
2:再创建一个.html文件computers
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> </head> <body> <input type="text" id="number1" placeholder="请输入第一个数字"/><br/> <select id="opt" > <option value="+">+</option> <option vaue="-">-</option> <option value="*">*</option> <option vallue="/">/</option> <option value="**">**</option> </select><br/> <input type="text" id="number2" placeholder="请输入第二个数字"/><br/> <input type="button" value="计算" οnclick="jisuan()"/> <span id="resultShow"></span> <script> function jisuan(){ var number1=document.getElementById("number1").value; var opt=document.getElementById("opt").value; var number2=document.getElementById("number2").value; if(isNaN(number1)||isNaN(number2)){ alert("请输入数字"); return; } number1 = Number(number1); number2 = Number(number2); var result = 0; switch (opt){ case "+": result = number1+number2; break; case "-": result = number1-number2; break; case "*": result = number1*number2; break; case "/": if (number2==0) { alert("除数不能为零"); }else{ result = result.toFixed(2); result = number1 / number2; } break; case"**": result=number1**number2; break; default: result = "请输入运算符号"; } document.getElementById("resultShow").innerText=result; } </script> </body> </html>运行结果展示
一个计算机程序就完成啦！
