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;
}
示例
当当前时间小于 20 时,输出 "Have a good day!",否则输出 "Have a good night!"
$t = date("H");
if ($t < "20") {
echo "Have a good day!";
} else {
echo "Have a good night!";
}
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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;
}
示例
当当前时间小于 10 时,输出 "Have a good morning!",当当前时间小于 20 时,输出 "Have a good day!"。否则将输出 "Have a good night!"
$t = date("H");
if ($t < "10") {
echo "Have a good morning!";
} elseif ($t < "20") {
echo "Have a good day!";
} else {
echo "Have a good night!";
}
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