1.ç®åå¥æ³è§åï¼ç¨è±æ¬å·çå®åéåï¼éç¨äºPHPææçæ¬ï¼ï¼
$a = 'flower';
echo "She received some $as";
// æ æï¼åæ¯sä¼è¢«å½æææçåéåç»æå
ç´ ï¼ä½æ¯è¿éçåéæ¯$a
echo "She received some ${a}s"; // ææ
echo "She received some {$a}s"; // ææï¼æ¨èç使ç¨æ¹æ³
æ们å¸æ表达çæ¯â她æ¶å°ä¸äºè±âï¼è¯å¢ä¸çfloweråºè¯¥éç¨å¤æ°å½¢å¼ï¼ä¹å°±æ¯è¯´åºè¯¥å¨åé¢å ä¸Sï¼ï¼ä½æ¯å¦æä¸å¯¹åéåä»»ä½çå®çè¯ï¼å°±ä¼åºç°ç¬¬ä¸ä¸ªechoçæ
åµãæ¾ç¶æ们å¸æè¾åºçæ¯$aèä¸æ¯$asãé£ä¹æ们é常æ¯æä¹æ¥å¤çè¿ä¸ªè¾åºçå¢ï¼
echo "She received some $a"."s";
echo "She received some ".$a."s";
// è¿ä¸¤ç§ä¹ æ¯æ§çåæ³åºè¯¥æ²¡æå è±æ¬å·çåæ³ç®æ´æäºå§ï¼
注æï¼ä¸ç®¡{æ¯åºç°å¨$åé¢è¿æ¯åé¢ï¼åªæ两è
ç´§æ¨çæ¶è±æ¬å·æä¼è¢«å½ææ¯çå®ç¬¦å·ãä¸è¦å¨ä¹é´å ç©ºæ ¼ï¼è¦ä¸ç¶å°±ä¼è¢«å½ä½æ®éçè±æ¬å·å¤ç
echo "She received some { $a}s";
// è¾åºçç»æ为ï¼She received some { flower}s
2.å¤æå¥æ³è§åï¼ç¨è±æ¬å·çå®è¡¨è¾¾å¼çï¼ä½¿ç¨ä¸PHP4+ï¼ï¼
echo "ææçåæ³ï¼ {$arr[4][3]}";
// ææï¼çå®å¤ç»´æ°ç»
echo "ææçåæ³ï¼ {$arr['foo'][3]}";
// ææï¼å½å¨å符串ä¸ä½¿ç¨å¤ç»´æ°ç»æ¶ï¼ä¸å®è¦ç¨æ¬å·å°å®æ¬èµ·æ¥
echo "ææçåæ³ï¼ {$this->width}00";
// ææï¼å¦æä¸çå®çè¯ï¼å°±ä¼åæ $this->width00
echo "ææçåæ³ï¼ {$this->value[3]->name}";
// ææï¼è¯¥ä¾æ¼ç¤ºäºçå®é¾å¼è°ç¨
echo "ææçåæ³ï¼ $name: {${$name}}";
// ææï¼è¯¥ä¾æ¼ç¤ºçææå®é
ä¸æ¯ä¸ä¸ªå¯ååé
echo "ææçåæ³: {${getName()}}";
// ææï¼è¯¥ä¾æ¼ç¤ºäºå°å½æ°çè¿åå¼ä½ä¸ºåéå
echo "ææçä¸åï¼ {${$this->getName()}}";
// ææï¼è¯¥ä¾æ¼ç¤ºäºå°å½æ°çè¿åå¼ä½ä¸ºåéå
注æ1ï¼echo "è¿æ ·åææåï¼ {getName()}";è¾åºç»æ为ï¼'è¿æ ·åææåï¼
{getName()}'ãå 为éé¢ä¸å«$ï¼æ以è±æ¬å·ä¸ä¼è¢«å½ä½çå®ç¬¦
注æ2ï¼echo "è¿æ ·åææåï¼{$arr[foo][3]}"; å¨åçè¿ä¸ªé®é¢åæ们å
æ¥è¿è¡ä¸ä¸ªå®éªï¼
error_reporting(E_ALL);
$arr = array('a', 'b', 'c', 'd'=>'e');
echo "This is $arr[d]";
// æ们åç°è¿æ ·åæ¯æ²¡æé®é¢çï¼é£ä¹æ们åä¸é¢è¿æ ·åå¢ï¼
echo $arr[d];
产çäºè¿æ ·çé误ï¼
Notice: Use of undefined constant d - assumed 'd'
注æï¼éç¨äºæªå®ä¹ç常édï¼å¯è½åºè¯¥ä¸º'd'
é£ä¹å¦ææ们åä¸é¢è¿æ ·ä¿®æ¹ä¸ä¸ä»£ç çè¯
error_reporting(E_ALL);
$arr = array('a', 'b', 'c', 'd'=>'e');
define('f', 'd');
echo $arr[f];
æ 们åç°è¿æ¬¡æ²¡æé®é¢äºãå¯ä»¥çåºå¨å符串ä¸æ°ç»çç´¢å¼ä¸å åå¼å·æ¯æ²¡æé®é¢çï¼ä½æ¯å¦æè¿ç§åæ³ä¸æ¯åºç°å¨å符串å½ä¸å°±ä¼æ¥éï¼è对äºåç¬¦ä¸²ä¸ {$arr[foo][3]}ç解æå°±æ¯æç
§éå符串çæ¹å¼è§£æçãæ以说å¨å符串å½ä¸å¯¹æ°ç»åªå è±æ¬å·çå®èä¸å¯¹ç´¢å¼å åå¼å·çåæ³æ¯é误çãå 为ç¨åº ä¼æä¸å åå¼å·çç´¢å¼å½ä½æ¯å¸¸éæ¥è¿è¡è§£æï¼è¿å°±äº§çäºé误ãæ£ç¡®çåæ³åºè¯¥æ¯ï¼
echo "ææçåæ³ï¼ {$arr['foo'][3]}";
ç¹ å«æéä¸ç¹ï¼echo "This is $arr[d]";è¿ç§åæ³è½ç¶è½å¤è¢«ç¨åºè§£æï¼ä½è¿ä¹ä»
éäºæ°ç»æ¯ä¸ç»´æ°ç»çæ
åµã严谨çåæ³åºè¯¥æ¯ï¼echo "This is {$arr['d']}";æçå¦çæ¾ç»å¨è¿ä¸ç¹ä¸åæäºè®ºè¿ï¼ä»è¯´ï¼æ¢ç¶åé¢ä¸ç§åæ³è½åºç»æï¼ä¸ºä»ä¹ä¸å®è¦ç¨åé¢ä¸ç§åæ³å¢ï¼é£ä¹ï¼æ们å继ç»ä¿®æ¹ä¸ ä¸åé¢ç代ç
error_reporting(E_ALL);
$arr = array('a', 'b', 'c',
'd'=>array('e'=>'f')
);
echo "This is $arr[d][e]";
è¿æ ·è¿è½å¤è¢«æ£ç¡®è§£æåï¼æåªæ³åè¯ä½ ï¼å è±æ¬å·æ¯ä¸¥è°¨çå¿
è¦çã
注æ3ï¼
error_reporting(E_ALL);
$arr = array('a', 'b', 'c', 'd');
echo "This is {$arr[2]}
";
echo "This is {$arr['2']}
";
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·ä½åºç¨å¨ä»ä¹å°æ¹å¢ï¼----SQLè¯å¥
// 示ä¾ä¸ï¼
$SQL1 = "select * from table where id={$_GET['id']}";
// 示ä¾äºï¼
$SQL2 = "select * from table where id={$this->id}";
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