2:数据类型 (data type)
数字(整形,浮点),字符串,布尔
Numeric(integer,float),string,boolean
2.1)Integer:
8x4 = 32
scope[-2^31 ][2^31]
2.2)String
escape
//phpinfo();
$var1 = "Hello World!";
echo $var1[0];
for($i=0;$i
echo $var1{$i}."
";
}
$ary[] = "abc";
$var1 = "Hello {$var1} $ary[0] World!";
echo <<
ABC
EOT;
?>
3:数组Array
数组的特性
数字索引 index
数组元素 同一类型 (PHP特性,数组可以不同类型)
集合的特性
index,key
how to del,add,access,iterate
$a[] = "cxne";
$a[] = "baidu";
$a[] = 1;
for($i=0;$i
echo gettype($a[$i]);
}
$b[1] = "sina";
$b["key"] = "google";
foreach ($b as $key1=>$x)
{
echo $key1."=".$x."
";
}
unset($b[1]) ;
$c = array(array("a","b"),"abc"=>"baidu","sina");
$c[0][1] = 100;
print_r($a);
print_r($b);
print_r($c);
echo $c["abc"]{0};
?>
4:布尔 boolean
$b = (bool)100;
echo $b;
if(FALSE || 0 || 0.0 || "0" || array()|| NULL || "NULL")
{
echo "这里面有真值么?";
}
unset($b);
echo gettype($c);
?>
5:类和对象object 定义definition 实现implement 成员member instantiate 调用 call
class car
{
var $speed=100; //属性 静态的描述
function run() //方法 行为特征
{
echo "汽车的以".$this->speed."速度开始跑路";
}
}
$one = new car();
$one->run();
?>
