php在指定字串中尋找子字串

對strpos()函數可以用來在php中尋找子字串。strpos()函數將試圖找到子字串在源字串中首次出現的位置。如果找到了，它會返回一個非負整數表示子字串出現的位置。 否則它會返回一個布爾值false。 $haystack1 = "2349534134345w3mentor16504381640386488129"; $haystack2 = "w3mentor234953413434516504381640386488129"; $haystack3 = "center234953413434516504381640386488129fyi"; $pos1 = strpos($haystack1, "w3mentor"); $pos2 = strpos($haystack2, "w3mentor"); $pos3 = strpos($haystack3, "w3mentor"); print("pos1 = ($pos1); type is " . gettype($pos1) . "\n"); print("pos2 = ($pos2); type is " . gettype($pos2) . "\n"); print("pos3 = ($pos3); type is " . gettype($pos3) . "\n"); ?> 複製代碼 輸出結果 pos1 = (13); type is integer pos2 = (0); type is integer pos3 = (); type is boolean pos3返回的是bool值，即沒有找到子字串 複製代碼

php

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