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JavaScript 逻辑空赋值运算符
tryjsref_assign_nullish
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<!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 = null; x ??= 10; document.getElementById("demo").innerHTML = "x is: " + x; </script> </body> </html>