"";

Question

Update for PHP 7

(thanks

shock_gone_wild

)

PHP 7 introduces the so called

null coalescing operator

which simplifies the below statements to:Before PHP 7No, there is no special operator or special syntax for this. However, you could use the ternary operator:

Or like this:

PHP 7.4+; with the null coalescing assignment operatorPHP 7.0+; with the

null coalescing operator

PHP 5.3+; with the ternary operator

shorthand

Or for

all [重复]

if(!isset($var) {
  $var = "";
}

$var = $var | "";

Answer 1

这个问题在这里已经有了答案

:

$var = $var ?? "default";

$var = isset($var) ? $var : "default";

PHP的简写是什么： print var if var exist？

isset($var) ?: $var = 'default';

Answer 2

封闭

$var ??= '';

6年前.

$var = $var ?? '';

如果一个变量在 PHP 中不存在，有没有一种速记的方法可以将它赋值给某个变量？我想做这样的事情

isset($var) ?: $var = '';

如果在PHP中不存在一个变量，有没有一种速记的方法来给它赋值？ if(!isset($var) { $var = ""; }。我想做这样的事情：$var = $var 旧版本的版本 与 设置:

$var = isset($var) ? $var : '';

或

!isset($var) && $var = '';