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数学 | Mathematics

max

max

(PHP 4, PHP 5, PHP 7)

max — Find highest value

Description

mixed max ( array $values )

mixed max ( mixed $value1 , mixed $value2 [, mixed $... ] )

If the first and only parameter is an array, max() returns the highest value in that array. If at least two parameters are provided, max() returns the biggest of these values.

Note: Values of different types will be compared using the standard comparison rules. For instance, a non-numeric string will be compared to an integer as though it were 0, but multiple non-numeric string values will be compared alphanumerically. The actual value returned will be of the original type with no conversion applied.

Caution

Be careful when passing arguments with mixed types values because max() can produce unpredictable results.

Parameters

values

An array containing the values.

value1

Any comparable value.

value2

Any comparable value.

...

Any comparable value.

Return Values

max() returns the parameter value considered "highest" according to standard comparisons. If multiple values of different types evaluate as equal (e.g. 0 and 'abc') the first provided to the function will be returned.

If an empty array is passed, then FALSE will be returned and an E_WARNING error will be emitted.

Examples

Example #1 Example uses of max()

<?php echo max(2, 3, 1, 6, 7  // 7 echo max(array(2, 4, 5) // 5 // The string 'hello' when compared to an int is treated as 0 // Since the two values are equal, the order they are provided determines the result echo max(0, 'hello'     // 0 echo max('hello', 0     // hello // Here we are comparing -1 < 0, so 'hello' is the highest value echo max('hello', -1    // hello // With multiple arrays of different lengths, max returns the longest $val = max(array(2, 2, 2), array(1, 1, 1, 1) // array(1, 1, 1, 1) // Multiple arrays of the same length are compared from left to right // so in our example: 2 == 2, but 5 > 4 $val = max(array(2, 4, 8), array(2, 5, 1) // array(2, 5, 1) // If both an array and non-array are given, the array will be returned // as comparisons treat arrays as greater than any other value $val = max('string', array(2, 5, 7), 42   // array(2, 5, 7) // If one argument is NULL or a boolean, it will be compared against // other values using the rule FALSE < TRUE regardless of the other types involved // In the below example, -10 is treated as TRUE in the comparison $val = max(-10, FALSE // -10 // 0, on the other hand, is treated as FALSE, so is "lower than" TRUE $val = max(0, TRUE // TRUE ?>

See Also

  • min() - Find lowest value

  • count() - Count all elements in an array, or something in an object

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https://secure.php.net/manual/en/function.max.php