php内的字符串中的条件语句 [英] Conditional statement inside string inside php

问题描述

我正在尝试评估日期[3]以确定选择的选项.所有这些都在php sql查询中.我无法在$ options字符串变量中找到一种简单的方法来获取date [3]中返回的值的选择.

I am trying to evaluate date[3] to determine selected option. All this is inside a php sql query. I am not able to find out an easy way to get a selected for the value returned in date[3] in my $options string variable.

<?php  //sql statement
    foreach( $db->query($sql) as $data ) {

        $options = "<select type='text' name='pagephone'  select id='pagephone' >
       <option value=''></option>
       <option ". if ($data[3] == 'vtext.com' ){ echo 'selected' };. " value='vtext.com'>Verizon Wireless</option>
       <option ". if ($data[3] == 'vmobl.com' ){ echo 'selected' };. " value='vmobl.com'>Virgin Mobile</option>
       <option ". if ($data[3] == 'sms.alltelwireless.com' ){ echo 'selected' };. " value='sms.alltelwireless.com'>Alltel</option>";
       ?>

推荐答案

您正试图用.连接一个值，因此您使用的值必须是一个计算结果为字符串的表达式. if 块不是这样的表达式，从语法错误中可以看到，如果您使用问题中的代码，则会得到语法错误.您可以使用三元表达式相反，像这样.

You're trying to concatenate a value with ., so the value you use needs to be an expression that evaluates to a string. An if block is not such an expression, as you can see from the syntax error you get if you use the code from your question. You can use a ternary expression instead, like this.

...<option ". ($data[3] == 'vtext.com') ? 'selected' : '' . " value='vtext.com'>
      Verizon Wireless</option>...

就个人而言，我宁愿迭代一个值/文本对数组，而不是像这样对所有选择选项进行硬编码:

Personally, I would prefer to iterate an array of value/text pairs rather than hardcoding all the select options, like this:

$values = [
    'vtext.com' => 'Verizon Wireless',
    'vmobl.com' => 'Virgin Mobile',
    'sms.alltelwireless.com' => 'Alltel'
];

foreach( $db->query($sql) as $data ) {
    $options = "<select type='text' name='pagephone' id='pagephone'><option value=''></option>";

    foreach ($values as $value => $text) {
        $selected = ($data[3] == $value) ? 'selected' : '';
        $options .= "<option value='$value' $selected>$text</option>";
    }
    $options .= '</select>';
}

但这只是我的看法.不过，请不要忘记关闭您的< select> .

But that's just my opinion. Don't forget to close your <select>, though.

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