Question

我正试图通过获取学生的年级和班级学分的数量并对其进行计算来计算学生的GPA。我遇到一个问题，即它无法正确计算creditsEarned和GPA。对于U或F级，所获得的学分应为0，但这不是输出的结果。我不确定我的陈述有什么问题。

#!/usr/bin/perl 
#This is going to be the user login check and will set a cookie

use DBI;
use CGI qw(:standard);

use strict;

#Connection error 
sub showErrorMsgAndExit {
    print header(), start_html(-title=>shift);
    print (shift);
    print end_html();
    exit;
}

#Connecting to the database
my $dbUsername = "root";
my $dbPassword = "password";

my $dsn = "DBI:mysql:f18final:localhost";
my $dbh = DBI->connect($dsn, $dbUsername, $dbPassword, {PrintError => 0});

#error checking
if(!$dbh) {
    print header(), start_html(-title=>"Error connecting to DB");
    print ("Unable to connec to the database");
    print end_html();
    exit;
}

print header;
print start_html(-title=>'Edit Classes');

#Need to execute sql command and then iterate row by row
my $sql = "SELECT * FROM tblclasses";
my $sth = $dbh->prepare($sql);
$sth->execute();

my $passedCredits = 0;
my $attemptedCredits = 0;
my $totalHonor = 0;
my $gpa = 0.000;


##SSSssssssearch part


print "<table border=solid 1px>"; #start of table
print "<tr><th>Class Name</th><th>Department</th><th>Class Number</th><th>Grade</th><th>Credits</th>";
print "</tr>";
while( my @row = $sth->fetchrow_array) {
    print "<tr><td>";
    print $row[1];
    print "</td>";
    print "<td>";
    print $row[2];
    print "</td>";
    print "<td>";
    print $row[3];
    print "</td>";
    print "<td>";
    print $row[4];
    print "</td>";
    print "<td>";
    print $row[5];
    print "</td>";

    $attemptedCredits = $attemptedCredits + $row[5];
    if($row[4] == 'A' || $row[4] == 'a') {
        $passedCredits = $passedCredits + $row[5];
        $gpa = $gpa + (4 * $row[5]);
    }
    elsif($row[4] == 'B' || $row[4] == 'b') {
        $passedCredits = $passedCredits + $row[5];
        $gpa = $gpa + (3 * $row[5]);
    }
    elsif($row[4] == 'C' || $row[4] == 'c') {
        $passedCredits = $passedCredits + $row[5];
        $gpa = $gpa + (2 * $row[5]);
    }
    elsif($row[4] == 'D' || $row[4] == 'd') {
        $passedCredits = $passedCredits + $row[5];
        $gpa = $gpa + (1 * $row[5]);
    }
    elsif($row[4] == 'F' || $row[4] == 'f') {

    }
    elsif($row[4] == 'S' || $row[4] == 's') {
        $passedCredits = $passedCredits + $row[5];
    }
    elsif($row[4] == 'U' || $row[4] == 'u') {

    }

    #calculate

    print "</tr>";

}


print "</table>";

#Need to make a table and populate it with text boxes of all the class data


print "</table>"; #End of table

$gpa = $gpa / $attemptedCredits;

##RReturn values
print qq{
<table border = '1px solid'>
<tr>
<td>
Attempted Credits
</td>
<td>
Passed Credits
</td>
<td>
GPA
</td>
</tr>
<tr>
<td>
$attemptedCredits
</td>
<td>
$passedCredits
</td>
<td>
$gpa
</td>
</tr>
</table>
};
print "<form action=http://localhost/cgi-bin/actions.pl method = 'post' >";
print "<input type = 'submit' name = 'submit' value = 'More Options'>";
print "</form>";
print "<form action=http://localhost/cgi-bin/searchingTran.pl method = 'post' >";
print "<input type = 'text' name = 'search' size = '25'><br>";
print "<input type = 'submit' name = 'submit' value = 'Search'>";
print "</form>";
print end_html();

这是我的输出

还有一种方法可以将GPA打印到小数点后三位？

Answer 1

对于U或F级，所获得的学分应为0，但这不是输出的结果。

生成输出时，您甚至在查看成绩等级之前就打印getSomething(): Observable<HttpResponse<Model>> { return this.httpClient.get<Model>(this.apiEndpoint, { observe: 'response' }).pipe( catchError(this.handleError.bind(this)) ); }的内容。要将其正确显示为0，您需要先检查成绩，然后打印$row[5]（如果成绩为“ F”或“ U”）或0（如果成绩为其他任何值））。

在实际代码中，我建议您使用模板系统（例如Template::Toolkit），而不是直接打印出HTML，这将有助于避免此类错误，但是我发现这看起来像一个作业，我怀疑是否可以在作业范围内使用类似的替代方法。

还有一种方法可以将GPA打印到小数点后三位？

使用$row[5]或printf：

sprintf

从数据库值perl cgi

1 个答案: