如何通過搜索將字符串放入數組中然後輸出它？

Question

$states = "Mississippi Alabama Texas Massachusetts Kansas"; 
$statesA = explode(' ',$states); 
$statesArray = array(); 

foreach($statesA as $state) { 
if(preg_match('/xas$/', trim($state))) 
$statesArray[0] = trim($state); 
} 

foreach($statesA as $state) { 
if(preg_match('/^k.*s$/i', trim($state))) 
$statesArray[1] = trim($state); 
} 

foreach($statesA as $state) { 
if(preg_match('/^M.*s$/', trim($state))) 
$statesArray[2] = trim($state); 
} 

foreach($statesA as $state) { 
if(preg_match('/a$/', trim($state))) 
$statesArray[3] = trim($state); 
} 

foreach($statesA as $state) { #PROBLEM HERE 
if(preg_match('/^M/', trim($state))) 
$statesArray[4] = trim($state); 
} 

foreach ($statesArray as $element => $value) 
print("Element $element of the Array is $value <br />"); 

任務是基本上輸出一個以變量狀態字母M開頭的單詞。我有"Mississippi Alabama Texas Massachusetts Kansas"在$states。當我嘗試打印出來時，Massachusetts被打印出來而不是Mississippi。這是爲什麼？

Answer 1

<? 
foreach($statesA as $state) { #PROBLEM HERE 
    if(preg_match('/^M/', trim($state))) 
    $statesArray[4] = trim($state); 
    } 
?> 

在上面代碼中，無論是馬薩諸塞州和密西西比州符合您的表達，並且它們都存儲在$statesArray[4]。如果你只想要第一場比賽，也許你還應該檢查$statesArray[4]是否已經設置。所以，這樣的事情應該工作：

<? 
    foreach($statesA as $state) { #PROBLEM HERE 
    if(preg_match('/^M/', trim($state)) && !isset($statesArray[4])) 
    $statesArray[4] = trim($state); 
    } 
?> 

這將填補$statesArray[4]只有當它尚未設置。

讓我知道這是否適合你。