php for循环为字符串值创建未定义的变量[重复]

Question

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• “Notice: Undefined variable”, “Notice: Undefined index”, and “Notice: Undefined offset” using PHP 28 answers

I am looping though my data and strong the result in a variable. It is currently being stored as strings.

for ($i = 0; $i < count($AnotherArray); $i++){

  $myArray  .= $dataArray[$i].",";
 }

This correctly returns the content with commas separating the values. But i get a notice

Notice: undefind variable: $myArray in ...

The above is the first time i create and call $myArray

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Answer 1

You need to have the variable defined before you can append to it

$myArray="";
for ($i = 0; $i < count($AnotherArray); $i++){

  $myArray  .= $dataArray[$i].",";
 }