{$variable} 在 PHP 中如何工作？

Question

当我想在字符串中使用变量值时，我将它们与 . （点）运算符。

我看到有些人在字符串中使用 {$variable} 。

所以..我的例子：

"my name is ".$variable

有些人使用它：

"my name is {$variable}"

上面两个例子有什么区别？

Answer 1

当您想要将字符串附加到字符串内变量的值时，可以使用它。

$variable = 'hack';

// now I want to append 'ed' to $variable:    

echo "my name is {$variable}";   // prints my name is hack

echo "my name is {$variable}ed"; // prints my name is hacked

echo "my name is $variable";     // prints my name is hack

echo "my name is $variableed";   // Variable $variableed not defined.

Answer 2

也许一些例子可以解释括号和 .连接字符串的运算符。

假设您有一个变量保存某个值，即 $money，并且您想要显示该金额。

$money=10;

print "you have earned $money"; // would output 'you have earned 10;
// ops missed the dollar sign as we are dealing with currency.
print "you have earned $money"; // hmmm, that wont work $ means something else.

因此，如果您有花括号，那么您可以更清楚地告诉 PHP 您想要将哪个变量替换到字符串中。

print "you have earned ${$money}.00"; would now output 'you have earned $10.00'

现在看起来好多了。