php - 为什么我的 Javascript 警报没有显示？

Question

基本上，我试图通过 PHP 调用 Javascript 警报。尽管如此，警报根本不起作用。

这是我动态创建警报的 echo 语句

echo "<script>alert('Uploaded file was not in the correct format\n\nExample of the correct format:\nquestion1,answer1,answer2,answer3,answer4\n
question2,answer1,answer2,answer3,answer4\nquestion3,answer1,answer2,answer3,answer4')</script>";

我发现如果我将警报更改为此，它会完美地工作:

echo "<script>alert('Uploaded file was not in the correct format')</script>";

我认为换行存在问题。

我将代码更改为这样，但仍然没有运气:

echo "<script>alert('Uploaded file was not in the correct format\\nExample of the correct format:\\nquestion1,answer1,answer2,answer3,answer4\\n
question2,answer1,answer2,answer3,answer4\\nquestion3,answer1,answer2,answer3,answer4')</script>";

我收到以下错误:

SyntaxError: unterminated string literal
[Break On This Error]   

alert('Uploaded file was not in the correct format\nExample of the
------^

createplay.php (line 1, col 6)

有人对为什么这不起作用有任何建议吗？网上查了很多资料都没有找到解决办法。

提前致谢!

Answer 1

您的 \n 字符将被 PHP 替换为文字换行符。

字符串文字中的未转义文字换行符是 JavaScript 中的错误。

使用 \\n 将换行转义序列发送到 JavaScript。