Question

我需要使用PHP打印出包含给定子字符串“ Happy”的所有字符串。

$t包含所有输入数据。我尝试这样做，但无法达到预期的输出。

请提供有关如何解决此问题的建议。预先感谢。

$i = 1;
while ($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

预期输出：

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。因此，您需要严格检查strpos的结果以查看是否匹配，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，然后就不需要调用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“ Happy”从索引0开始时，strpos返回0，从而使if校验为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);

PHP-如何检查字符串是否包含子字符串并打印

3 个答案: