PHP if...else 语句

PHP - if...else 语句

当条件为真时，if...else 语句会执行一些代码，否则会执行另一段代码。

语法

if (condition) {
  // code to be executed if condition is true;
} else {
  // code to be executed if condition is false;
}

$t = date("H");

if ($t< "20") {
  echo "Have a good day!";
} else {
  echo "Have a good night!";
}

PHP - if...elseif...else 语句

对于两个以上的条件，if...elseif...else 语句会执行不同的代码。

语法

if (condition) {
  code to be executed if this condition is true;
} elseif (condition) {
  // code to be executed if first condition is false and this condition is true;
} else {
  // code to be executed if all conditions are false;
}

$t = date("H");

if ($t< "10") {
  echo "Have a good morning!";
} elseif ($t< "20") {
  echo "Have a good day!";
} else {
  echo "Have a good night!";
}