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下边提到的几个PHP数组排序函数的排序有一些共性： 1 数组被作为排序函数的参数，排序以后，数组本身就发生了改变，函数的返回值为bool类型。 2 函数名中出现单a表示association，含义为，在按值排序的过程中，保持key=>value的对应关系不变 3 函数名中出现单k表示key，含义为，在按值排序的过程中按照数组key而不是数组的值排序 4 函数名中出现单r的表示reverse，含义为，按照跟不加r的相反的顺序排列 5 函数名中出现单u的表示user-defined，含义为，使用用户自定义函数排序，如果函数的逻辑是参数1<参数2返回负数，则按照升序排列(p1小2返负升)。 --------------------sort函数升序排序-------------------------------- bool sort ( array &$array [, int $sort_flags= SORT_REGULAR ] ) <?php$fruits = array("lemon", "orange", "banana", "apple");sort($fruits);var_dump($fruits);?>结果：array0 => string 'apple' (length=5)1 => string 'banana' (length=6)2 => string 'lemon' (length=5)3 => string 'orange' (length=6)--------------------rsort降序排列-------------------- <?php$fruits = array("lemon", "orange", "banana", "apple");rsort($fruits);var_dump($fruits);?>结果：array0 => string 'orange' (length=6)1 => string 'lemon' (length=5)2 => string 'banana' (length=6)3 => string 'apple' (length=5)---------------asort按照二维数组值的升序排列（保持key=>value的关联关系）----------- <?php$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");asort($fruits);var_dump($fruits);?>结果：array'c' => string 'apple' (length=5)'b' => string 'banana' (length=6)'d' => string 'lemon' (length=5)'a' => string 'orange' (length=6)--------------arsort按照二维数组值的降序排列（保持key=>value的关联关系）-------------- <?php$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");arsort($fruits);var_dump($fruits);?>结果array'a' => string 'orange' (length=6)'d' => string 'lemon' (length=5)'b' => string 'banana' (length=6)'c' => string 'apple' (length=5)--------------------ksort按照数组的key升序排列-------------- <?php$fruits = array("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple");ksort($fruits);var_dump($fruits);?>结果array'a' => string 'orange' (length=6)'b' => string 'banana' (length=6)'c' => string 'apple' (length=5)'d' => string 'lemon' (length=5)---------------------krsort按照数组key的降序排列-------------------------------- <?php$fruits = array("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple");krsort($fruits);var_dump($fruits);?>结果array'd' => string 'lemon' (length=5)'c' => string 'apple' (length=5)'b' => string 'banana' (length=6)'a' => string 'orange' (length=6)----------------usort函数按照用户自定义的函数排序---------------- <?phpfunction cmp($a, $b){if ($a == $b) {return 0;}return ($a < $b) ? -1 : 1;} $a = array(3, 2, 5, 6, 1); usort($a, "cmp"); var_dump($a);?>结果：array0 => int 11 => int 22 => int 33 => int 54 => int 6-----------------uksort使用自定义函数按照数组的key排序----------------- <?phpfunction cmp($a, $b){$a = preg_replace('@^(a|an|the) @', '', $a);$b = preg_replace('@^(a|an|the) @', '', $b);return strcasecmp($a, $b);} $a = array("John" => 1, "the Earth" => 2, "an apple" => 3, "a banana" => 4); uksort($a, "cmp"); var_dump($a);?>结果：array'an apple' => int 3'a banana' => int 4'the Earth' => int 2'John' => int 1-------------------uasort将数组用自定义函数按照value排序，保持索引关系不变--------- <?php// Comparison functionfunction cmp($a, $b) {if ($a == $b) {return 0;}return ($a < $b) ? -1 : 1;} // Array to be sorted$array = array('a' => 4, 'b' => 8, 'c' => -1, 'd' => -9, 'e' => 2, 'f' => 5, 'g' => 3, 'h' => -4);var_dump($array); // Sort and print the resulting arrayuasort($array, 'cmp');var_dump($array);?>结果：array'a' => int 4'b' => int 8'c' => int -1'd' => int -9'e' => int 2'f' => int 5'g' => int 3'h' => int -4array'd' => int -9'h' => int -4'c' => int -1'e' => int 2'g' => int 3'a' => int 4'f' => int 5'b' => int 8-------------------array_multisort排序多个数组或多维数组--------- <?php$ar = array(array("10", 11, 100, 100, "a"),array( 1, 2, "2", 3, 1)); array_multisort($ar[0], SORT_ASC, SORT_STRING,$ar[1], SORT_NUMERIC, SORT_DESC);var_dump($ar);?>结果：array0 => array0 => string '10' (length=2)1 => int 1002 => int 1003 => int 114 => string 'a' (length=1)1 => array0 => int 11 => int 32 => string '2' (length=1)3 => int 24 => int 1//说明： 1 上例中：$ar数组优先按照$ar[0]的字符串值升序排列，如果字符串值相等，再按照$ar[1]数组的数字值降序排列。 2 array_multisort函数的任意一个位置的参数如果是数组，表示排序时用的值， 如果有多个数组参数，优先按照前边的数组值进行排序，如果是常量，例如 SORT_ASC, SORT_DESC, SORT_REGULAR,SORT_NUMERIC, SORT_STRING. 表示排序方法（数组取值前优先）。
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