PHP-004- [data type] - string type conversion

Learning Points

• 1.bool type to String
• 2. Integer to String
• 3. float to String
• 4. array to a string
• The decentralization of resources to String [Note xml file in a directory more]
• 6. Object to String
• 7.NULL to String

<?php
echo '转化布尔型TRUE为字符串';
echo "<br>";
var_dump((string)TRUE);//string '1' (length=1)
echo "<br>";

echo '转化布尔型FALSE为字符串';
echo "<br>";
var_dump((string)FALSE);//string '' (length=0)
echo "<br>";

echo '转化整型为字符串';
echo "<br>";
var_dump((string)1202);//string '1202' (length=4)
echo "<br>";

echo '转化浮点数为字符串';
echo "<br>";
var_dump((string)10.27);//string '10.27' (length=5)
echo "<br>";
var_dump((string)2.3e5);//string '230000' (length=6)
echo "<br>";

echo '转化数组为字符串';
echo "<br>";
$numbers = array('1','2','3');
var_dump($numbers);
echo "<br>";
var_dump((string)$numbers);//错误
echo "<br>";

echo '转化对象为字符串';
echo "<br>";
$object = (object)"Human";
var_dump($object); //object(stdClass)[1] public 'scalar' => string 'Human' (length=5)
echo "<br>";//错误的

echo '转化资源为字符串';
echo "<br>";
//建立一个资源
$fp = fopen("peoples.xml","r");
var_dump((string)$fp); //string 'Resource id #3' (length=14)
echo "<br>";

echo '转化NULL为字符串';
echo "<br>";
var_dump((string)NULL);//string '' (length=0)

//关闭资源
fclose($fp);
?>