如何計算字符串中單詞出現的次數而忽略案例

Question

我想要統計給定單詞的出現次數，而忽略案例。 我試圖

<?php 
$string = 'Hello World! EARTh in earth and EARth';//string to look into. 
    if(stristr($string, 'eartH')) { 
    echo 'Found';// this just show eartH was found. 
    } 
    $timesfound = substr_count($string, stristr($string, 'eartH'));// this count how many times. 

    echo $timesfound; // this outputs 1 instead of 3. 

Answer 1

小寫搜索之前字符串：

$string = 'Hello World! EARTh in earth and EARth'; 
$search = 'EArtH'; 
var_dump(substr_count(strtolower($string), strtolower($search))); // outputs 3 

Answer 2

嘗試substr_count（）

 <?php 
    $text = 'This is a test'; 
    echo strlen($text); // 14 

    echo substr_count($text, 'is'); // 2 

    ?>