“？”的含义是什么？在 php 的声明中

Question

function countproduct(){
        $count = 0;
        $cart = isset($_SESSION['cart']) ? $_SESSION['cart']:array();
        foreach($cart as $row):
            if($row['qty']!=0){
                $count = $count + 1;
            }
        endforeach;

        return $count;

我想知道是什么意思？在 isset($_SESSION['cart'])

之后

Answer 1

这是一个三元运算符，这些行：

$cart = isset($_SESSION['cart']) ? $_SESSION['cart']:array();

可以转化为：

if (isset($_SESSION['cart'])) {
    $cart = $_SESSION['cart'];
} else {
    $cart = array();
}

更多信息您可以查看php operations documentation

“？”的含义是什么？在 php 的声明中

What is the meaning of the "?" in this statement in php

php

foreach

if-statement

class

session-cookies