在Echo语句中使用三元运算符

Question

I'm trying to use a ternary operator but the outcome is not right. I've followed the manual but have no idea what's going on. The outpout in the console is messy.

php

echo '<div class="item'.(($month_number==='09' && $month_year==='2017')?' active"':"").'>';

console output

<div class="item><div class=" m_page="" outer-div"="">
<div class="inner-div" style=""><div class="momo_p"> 

Answer 1

三元运算符后，将class属性的双引号引起来：

echo '<div class="item' . (($month_number==='09' && $month_year==='2017') ? ' active' : '') . '">';

Answer 2

echo '<div class="item'.(($month_number==='09' && $month_year==='2017')?' active"':'"').'>';

也许？

Answer 3

检查您的报价。

echo '<div class="item'.(($month_number==='10' && $month_year==='2017') ? "active" : "").'">

Answer 4

Use below code:

PHP

$active = ($month_number==='09' && $month_year==='2017') ? 'active': '';
echo '<div class="item '.$active.'">';

Answer 5

Here is a reworking of the one liner with the addition of two variables to test the code such that a true result concatenates "active" to "item". A false result leads to "item" being concatenated with an empty string, as follows:

<?php
$month_number = "08";
$month_year   = "2016";

echo "<div class=\"item";

// making the ternary expression more manageable
$month_result = ($month_number === "09");
$year_result  = ($month_year === "2017");
echo  ($month_result && $year_result)? "active":"";

echo "\"></div>";

Live code here

Note: if you wish to do one echo statement you could code as follows:

$str =  ($month_result && $year_result)? "active":"";
echo "<div class=\"item" . $str  . "\"></div>";

See live code here

While you could use double quotes for attributes and single quotes for everything else, it is easier to see escaped double quotes for attributes, ie \\" and double quotes for the outer strings.