Master PHP’s strcmp(): Compare Strings Like a Pro

strcmp()

is a PHP function that compares two strings based on their ASCII values.

PHP compares strings character by character using ASCII codes to determine their ordering.

strcmp() Function Syntax

strcmp(string $str1, string $str2): int

The parameters $str1 and $str2 represent the two strings to compare. The function returns an integer indicating the relationship:

If the return value is 0, the strings are equal.

If the return value is less than 0, $str1 is less than $str2.

If the return value is greater than 0, $str1 is greater than $str2.

Examples of Using strcmp()

Example 1

$str1 = "apple";
$str2 = "banana";
$result = strcmp($str1, $str2);
if ($result == 0) {
    echo "两个字符串相等";
} elseif ($result < 0) {
    echo "$str1 小于 $str2";
} else {
    echo "$str1 大于 $str2";
}

Output: apple 小于 banana

Example 2

$str1 = "apple";
$str2 = "apple";
$result = strcmp($str1, $str2);
if ($result == 0) {
    echo "两个字符串相等";
} elseif ($result < 0) {
    echo "$str1 小于 $str2";
} else {
    echo "$str1 大于 $str2";
}

Output: 两个字符串相等

Example 3

$str1 = "banana";
$str2 = "apple";
$result = strcmp($str1, $str2);
if ($result == 0) {
    echo "两个字符串相等";
} elseif ($result < 0) {
    echo "$str1 小于 $str2";
} else {
    echo "$str1 大于 $str2";
}

Output: banana 大于 apple

The strcmp() function returns 0 for equal strings, a negative value when the first string is smaller, and a positive value when it is larger.