<!DOCTYPE html> <html> <body> <h1>JavaScript 字符串</h1> <p>字符串写在单引号或双引号内:</p> <p id="demo"></p> <script> let carName1 = "Volvo XC60"; // 双引号 let carName2 = 'Volvo XC60'; // 单引号 document.getElementById("demo").innerHTML = carName1 + " " + carName2; </script> </body> </html>