如何替换“如果"带有三元运算符 (?:) 的语句? [英] How to replace "if" statement with a ternary operator ( ? : )?

问题描述

基于本页的示例，我想转换以下内容if 语句到三元运算符.

Based on the examples from this page, I wanted to convert the below if statement to a ternary operator.

使用if语句的工作代码:

if (!empty($address['street2'])) echo $address['street2'].'<br />';

我不确定应该如何使用三元运算符编写它，以便 echo 仅在 street2 存在于数组中并且不是空字符串时才起作用.

I am not sure how this should be written using a ternary operator so that the echo works only if street2 exists in the array and is not an empty string.

推荐答案

(condition) ? /* value to return if condition is true */ 
            : /* value to return if condition is false */ ;

语法不是简写 if"操作符(? 被称为条件操作符)，因为你不能像你那样执行代码:

syntax is not a "shorthand if" operator (the ? is called the conditional operator) because you cannot execute code in the same manner as if you did:

if (condition) {
    /* condition is true, do something like echo */
}
else {
    /* condition is false, do something else */
}

在您的示例中，当 $address 不为空时，您正在执行 echo 语句.您不能使用条件运算符以相同的方式执行此操作.但是，您可以做的是 echo 条件运算符的结果:

In your example, you are executing the echo statement when the $address is not empty. You can't do this the same way with the conditional operator. What you can do however, is echo the result of the conditional operator:

echo empty($address['street2']) ? "Street2 is empty!" : $address['street2'];

这将显示街道是空的！"如果为空，则显示street2地址.

and this will display "Street is empty!" if it is empty, otherwise it will display the street2 address.

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