php in_array,trim,isset,unset,is_numeric函数用法。
php in_array,trim,isset,unset,is_numeric函数用法。
下面我们一一看讲一下这些函数的使用教程吧。
in_array($array)
这个函数是判断当前值是否为数组哦
EX:
$array= array(1,2);
if( in_array( $array ) )
{
die('in_array判断它是数组');
}
echo '不是数组';
result:
in_array判断它是数组
trim($value)
trim函数是去除参数的空值包括null," "
isset($value)
isset是判断变量是否存在
unset($value)
销毁变量
下面我们来看看isset,unset实例吧。
$a = 'v';
isset( $a ) ? $a:NULL;
unset( $a );
isset( $a ) ? $a:NULL;
结果是:
v
Null
is_numeric($num)
$num =3;
if( is_numeric($num) )
{
echo $num;
}
else
{
echo '不是数值';
}
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