主页
JavaScript
JavaScript 2020 新特性
tryjs_assign_nullish
运行 ❯
×
更改方向
保存代码
更改主题
<!DOCTYPE html> <html> <body> <h1>JavaScript Assignments</h1> <h2>The Nullish Operator</h2> <h3>The ??= Operator</h3> <p>If the first value is undefined or null, the second value is assigned.</p> <p id="demo"></p> <script> let x; x ??= 10; document.getElementById("demo").innerHTML = "x is: " + x; </script> </body> </html>