PHP-如何检查字符串是否包含子字符串并打印它[重复]

Question

这个问题在这里已有答案：

• php 5 strpos() difference between returning 0 and false? 5个答案

我需要使用PHP打印出包含给定子串“Happy”的所有字符串。

$t包含所有输入数据。我尝试过，但无法达到预期的输出。

请告知如何解决这个问题。提前致谢。

$i = 1;
while ($t = dbNext($r)) {
        $temp = strtolower($t[0]);
        if(strpos($temp, 'happy')){
                echo "$i - $t[0]";
                echo "\n";
                $i++;
        }
}

输入：

1. Happy Gilmore
2. The Fast and the Furious
3. Happy, Texas
4. The Karate Kid
5. The Pursuit of Happyness
6. Avengers: End Game
7. Happy Feet
8. Another Happy Day

预期产出：

1. Happy Gilmore
2. Happy, Texas
3. The Pursuit of Happyness
4. Happy Feet
5. Another Happy Day

我得到的输出：

1. The Pursuit of Happyness
2. Another Happy Day

Answer 1

strpos如果不匹配则返回false，但如果字符串与第一个字符匹配，则返回0。所以你需要严格检查strpos的结果，看看你是否有匹配，因为在布尔上下文中0与false相同：

if (strpos($temp, 'happy') !== false) {

请注意，您实际上可以使用不区分大小写的stripos，然后您将不需要调用strtolower。

Answer 2

在PHP中，strpos在匹配时返回子字符串的起始索引，否则返回False。因此，当“快乐”从索引0开始时，strpos返回0制作你的if if check false。做这样的事情：

$i = 1;
while ($t = dbNext($r)) {
        $temp = strtolower($t[0]);
        $res = strpos($temp, 'happy');
        if(gettype($res) == "integer" && $res >= 0){
                echo "$i - $t[0]";
                echo "\n";
                $i++;
        }
}

Answer 3

$str = 'this is the string';
$flag = 'i';

//Will return false if there is no $flag or the position of the first occurrence
$test = strpos($str, $flag); // returns 2

if( $test !== false ){

    echo substr($str, $test); //is is the string


}else{
    //There is no i in the string
}

使用循环

$input = array(
    'Happy Gilmore',
    'The Fast and the Furious',
    'Happy, Texas',
    'The Karate Kid',
    'The Pursuit of Happyness',
    'Avengers: End Game',
    'Happy Feet',
    'Another Happy Day',
);


$flag = 'happy';

//Loop 
foreach( $input AS $i ){

    //Test for occurrence
    $test = stripos($i, $flag); // returns false or number

    if( $test !== false ){


        $values[] = $i; //Returns the full string - alternatively you could use substr to extract happy or even explode using happy to count the amount of times it occurs


    }else{
        //There is no $flag in the string
    }
}

print_r($values);