php变量
局部变量仅能在函数内部访问,而全局变量则只能在函数外部访问,不能在函数内部访问
例子
<!DOCTYPE html>
<html>
<body>
<?php
$x=5; // global scope
function myTest()
{
$y=10; // local scope
echo "<p>Test variables inside the function:<p>";
echo "Variable x is: $x";
echo "<br>";
echo "Variable y is: $y";
}
myTest();
echo "<p>Test variables outside the function:<p>";
echo "Variable x is: $x";
echo "<br>";
echo "Variable y is: $y";
?>
</body>
</html>
php常量
在函数内部和外部都能被访问
例子
<?php
define("GREETING", "欢迎访问 Runoob.com");
function myTest() {
echo GREETING;
}
myTest(); // 输出 "欢迎访问 Runoob.com"
?>