I encountered a problem while reading PHP-related tutorial books. Please forgive me for being too clumsy. Forgive me for using a capitalized book title number instead of <>, otherwise a line break will be automatically displayed.
echo "a: [".(20>9)."]《br》";
The above is a simple Boolean expression
Why should the line break symbol of "br" be written in ""? And if it is written between "and;, an error will be reported?
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光陰似箭催人老，日月如移越少年。
你要明白為什麼寫在""雙引號內(nèi)，由於寫起雙引號內(nèi)，編譯才會視<br>為字符串輸出出來。但在引號外,<br>不是變量和常量，所以就是出現(xiàn)報錯！
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