注意：对已定义的变量使用未定义的常量

Question

我有这段代码。

    $rollcount=0;
    $rollcounts=array(); //I define $rollcounts here
    $number_of_tries = 100;

    foreach(range(0,$number_of_tries-1) as $i){
        do{ 
        $roll=rand(1,6);
        $rollcount++;
    }while($roll!=6);
    array_push($rollcounts, $rollcount);
    $rollcount = 0;
    }

    $freqs = array();
    while (!empty($rollcounts)){

        $freq = count(array_filter($rollcounts,function($a) use ($rollcounts)
            {return $a == $rollcounts[0];}
        ));
        $freqs[$rollcounts[0]] = $freq; 
        for($i=0;$i<count($rollcounts);$i++){ 

            if(rollcounts[$i] == $rollcounts[0]){ // THIS IS LINE 40
                unset($rollcounts[$i]);
            }

        }

    } // redo until $rollcounts is empty

生成此错误消息（第40行已在代码中注释）

  

注意：使用未定义的常量rollcounts - 假设'rollcounts'   在/Applications/XAMPP/xamppfiles/htdocs/learningphp/myfirstfile.php中   在第40行

显然，代码中已经定义了$rollcounts。那么这里的问题是什么？

Answer 1

您忘了 $

旧代码

        if(rollcounts[$i] == $rollcounts[0]){ // THIS IS LINE 40
            unset($rollcounts[$i]);
        }

新代码

        if($rollcounts[$i] == $rollcounts[0]){ // THIS IS LINE 40
            unset($rollcounts[$i]);
        }