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Collection
Collection
$arr = [0, 1, 2, 3, 4,'id' => 1,'name' => 'admin','age' => 33,'salary' => 9999,'in_use' => true,'roles' => [1, 2, 34, 5, 6],];// 1. 常规用法, 返回所有键名$keys = array_keys($arr);printfpre($keys);/*result:Array([0] => 0[1] => 1[2] => 2[3] => 3[4] => id[5] => name[6] => age[7] => salary[8] => in_use[9] => roles)*/// 2. 只返回键值对的值为某值的键名/* demo1: 非严格比较, '33' == 33 */$value = '33';$keys = array_keys($arr, $value);printfpre($keys);/*result:Array([0] => age[1] => in_use)*//* demo2: 严格比较, '33' !== 33 */$keys = array_keys($arr, $value, true);printfpre($keys);/*result:Array()*/$value = 33;$keys = array_keys($arr, $value, true);printfpre($keys);/*Array([0] => age)*/
$arr = [0, 1, 2, 3, 4,'id' => 1,'name' => 'admin','age' => 33,'salary' => 9999,'in_use' => true,'roles' => [1, 2, 34, 5, 6],];$targetKey = 'name';echobr(array_key_exists($targetKey, $arr) ? '存在' : '不存在');/*result: 存在*/
$arr = [0, 1, 2, 3, 4,'id' => 1,'name' => 'admin','age' => 33,'salary' => 9999,'in_use' => true,'roles' => [1, 2, 34, 5, 6],];echobr(array_key_first($arr));/*result: 0*/
echobr(array_key_last($arr));/*result: roles*/
$arr = [0, 1, 2, 3, 4,'id' => 1,'name' => 'admin','age' => 33,'salary' => 9999,'in_use' => true,'roles' => [1, 2, 34, 5, 6],];printfpre(array_values($arr));/*result:Array([0] => 0[1] => 1[2] => 2[3] => 3[4] => 4[5] => 1[6] => admin[7] => 33[8] => 9999[9] => 1[10] => Array([0] => 1[1] => 2[2] => 34[3] => 5[4] => 6))*/
$arr = [0, 1, 2, 3, 4,'id' => 1,'name' => 'admin','age' => 33,'salary' => 9999,'in_use' => true,'roles' => [1, 2, 34, 5, 6],];$targetValue = '33';echobr((in_array($targetValue, $arr) ? '存在' : '不存在'));/*默认为不严格比较, '33' == 33result: 存在*/echobr(in_array($targetValue, $arr, true) ? '存在' : '不存在');/*使用严格比较, '33' !== 33result: 不存在*/
$arr = [0, 1, 2, 3, 4,'id' => 1,'name' => 'admin','age' => 33,'salary' => 9999,'in_use' => true,'roles' => [1, 2, 34, 5, 6],];$targetValue = '33';dumpbr(array_search($targetValue, $arr));/*不使用严格模式, '33' == 33result: string(3) "age" */dumpbr(array_search($targetValue, $arr, true));/*严格模式, '33' !== 33, 返回falseresult: bool(false)*/
printfpre(array_unique($arr));/*'id'被删除了result:Array([0] => 0[1] => 1[2] => 2[3] => 3[4] => 4[name] => admin[age] => 33[salary] => 9999[roles] => Array([0] => 1[1] => 2[2] => 34[3] => 5[4] => 6))*/
$arr = [0, 1, 2, 3, 4,'id' => 1,'name' => 'admin','age' => 33,'salary' => 9999,'in_use' => true,'roles' => [1, 2, 34, 5, 6],];echobr(count($arr));/*不包括roles值中数组元素的个数result: 11*/echobr(count($arr, COUNT_RECURSIVE));/*包括二维数组(roles值中数组元素的个数)result: 16*/
printfpre(array_count_values($arr));/*key=原数组值; value=原数组值在原数组中出现的次数; roles的值不能统计result:Warning: array_count_values(): Can only count STRING and INTEGER values! in D:\phpstudy_pro\WWW\php11\PHP\0424\homework.php on line 253Array([0] => 1[1] => 2[2] => 1[3] => 1[4] => 1[admin] => 1[33] => 1[9999] => 1)*/
$arr = [0, 1, 2, 3, 4,'id' => 1,// 'name' => 'admin','age' => '33','salary' => 5000,'in_use' => true,'roles' => 1, //[1, 2, 34, 5, 6],'key1' => '100php123',// 'key2' => 'php100',];echobr(array_sum($arr));/*会自动跳过非数字值(数字字符串也被视为数字值, true = 1, false = 0), 数组也被忽略, 以数字开头的字符串, 会解析开头的数字部分(100php123=>100)result: 5145*/
echobr(array_product($arr));/*result: 0 */
$arr = [];$count = array_push($arr, 1, 2, 3, 4, 5, 6, 7, 8);echobr('共' . $count . '个元素入栈');dumpbr($arr);/*result:共8个元素入栈array(8) { [0]=> int(1) [1]=> int(2) [2]=> int(3) [3]=> int(4) [4]=> int(5) [5]=> int(6) [6]=> int(7) [7]=> int(8) }*/
$lastValue = array_pop($arr);echobr('最后一个元素的值是: ' . $lastValue);/* result: 最后一个元素的值是: 8 */
$count = array_unshift($arr, 'a', 'b', 'c', 'd');echobr('共在头部添加' . $count . '个元素');dumpbr($arr);/* result:共在头部添加11个元素array(11) { [0]=> string(1) "a" [1]=> string(1) "b" [2]=> string(1) "c" [3]=> string(1) "d" [4]=> int(1) [5]=> int(2) [6]=> int(3) [7]=> int(4) [8]=> int(5) [9]=> int(6) [10]=> int(7) } */
$delValue = array_shift($arr);echobr('被删除的数组元素值是: ' . $delValue);/*result: 被删除的数组元素值是: a*/
$arr = [0, 1, 2, 3, 4,'id' => 1,'name' => 'admin','height' => '174cm','age' => 33,'salary' => 9999,'in_use' => true,'roles' => [1, 2, 5, 34, 6],];// demo1: 升序, 键名重排if (sort($arr)) {echobr('排序成功');printfpre($arr);/*默认排序策略: 字母开头的字符串被解析为0; 数字开头的字符串, 开头的数字部分被解析为数字; boolean值比所有数字大; 数组值比Boolean值大;注意: 键值已经重排了result:Array([0] => admin[1] => 0[2] => 1[3] => 1[4] => 2[5] => 3[6] => 4[7] => 33[8] => 174cm[9] => 9999[10] => 1[11] => Array([0] => 1[1] => 2[2] => 5[3] => 34[4] => 6))*/} else {echobr('排序失败');}// demo2: 升序, 键名保持不变$arr = [0, 1, 2, 3, 4,'id' => 1,'name' => 'admin','height' => '174cm','age' => 33,'salary' => 9999,'in_use' => true,'roles' => [1, 2, 5, 34, 6],];if (asort($arr)) {echobr('排序成功');printfpre($arr);/*result:Array([name] => admin[0] => 0[1] => 1[id] => 1[2] => 2[3] => 3[4] => 4[age] => 33[height] => 174cm[salary] => 9999[in_use] => 1[roles] => Array([0] => 1[1] => 2[2] => 5[3] => 34[4] => 6)) */} else {echobr('排序失败');}// 排序策略测试略.// rsort()和arsort()使用方法类似, 略.
// 1. 键名升序$arr = [0, 1, 2, 3, 4,'id' => 1,'name' => 'admin','height' => '174cm','age' => 33,'salary' => 9999,'in_use' => true,'roles' => [1, 2, 5, 34, 6],];if (ksort($arr)) {echobr('键名升序排序成功');printfpre($arr);/*默认排序策略的解释, 见6.1-demo1resunt:Array([age] => 33[0] => 0[height] => 174cm[id] => 1[in_use] => 1[name] => admin[roles] => Array([0] => 1[1] => 2[2] => 5[3] => 34[4] => 6)[salary] => 9999[1] => 1[2] => 2[3] => 3[4] => 4)*/}// rksort()使用方法跟ksort()相同, 略.
// 回调函数说明:function (数组中的值1, 数组中的值2) {/*在第一个参数小于，等于或大于第二个参数时，该比较函数必须相应地返回一个小于，等于或大于 0 的整数。*/}
/* demo1: 模拟升序排列, 键名重排 */$arr = ['key1' => 10, 'key2' => 1, 'key3' => 21, 'key4' => 13, 'key5' => 4];// 模拟升序排列usort($arr, function ($val1, $val2) {return $val1 <=> $val2;});printfpre($arr);/* result: Array([0] => 1[1] => 4[2] => 10[3] => 13[4] => 21) *//* demo2: 模拟降序排列, 键名不重排 */$arr = ['key1' => 10, 'key2' => 1, 'key3' => 21, 'key4' => 13, 'key5' => 4];// 模拟降序排列, 键名保持不变uasort($arr, function ($val1, $val2) {return $val2 <=> $val1;});printfpre($arr);/*result:Array([key3] => 21[key4] => 13[key1] => 10[key5] => 4[key2] => 1)*/// - uksort(待处理数组, 写有排序逻辑的回调函数): 自定义函数对键名进行排序. 略
在字符串中的数字字符串将被当做数字值来排序.
$arr = ['r10c1', 'r1c1', 'r10c3', 'r2c2', 'r1c2', 'r10c2', 'r2c3', 'r2c1', 'r1c3', 'r2c4', 'r1c4', 'r10c4'];if (natsort($arr)) {printfpre($arr);/*字符串中的'10'将被当做数字10来排序, 而不是字符串从左到右按字符ASCII码排序(sort就是后者)result:Array([1] => r1c1[4] => r1c2[8] => r1c3[10] => r1c4[7] => r2c1[3] => r2c2[6] => r2c3[9] => r2c4[0] => r10c1[5] => r10c2[2] => r10c3[11] => r10c4)*/}
$arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];if (shuffle($arr)) {echobr(implode(', ', $arr));/* result: 5, 4, 2, 1, 8, 10, 3, 7, 6, 9 */}// - array_flip(待处理数组): 交换数组中的键和值, 返回交换后的数组$arr = ['key1' => 10, 'key2' => 1, 'key3' => 21, 'key4' => 13, 'key5' => 4];$res = array_flip($arr);printfpre($res);/*result:Array([10] => key1[1] => key2[21] => key3[13] => key4[4] => key5)*/
$arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];/* demo1: 不保留索引数组的键 */$res = array_reverse($arr);printfpre($res);/* result:Array([0] => 10[1] => 9[2] => 8[3] => 7[4] => 6[5] => 5[6] => 4[7] => 3[8] => 2[9] => 1)*//* demo2: 保留索引数组的键 */printfpre(array_reverse([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], true));/* result:Array([9] => 10[8] => 9[7] => 8[6] => 7[5] => 6[4] => 5[3] => 4[2] => 3[1] => 2[0] => 1)*/
开始截取的索引和截取长度都可以是负数, 截取长度为负数时, 表示从截取的终点索引(从末尾往回数)
$arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12];/* demo1: 从第3个开始截取, 截取4个元素组成数组 */$res = array_slice($arr, 2, 4);printfpre($res);/*注意: 索引重排了Array([0] => 3[1] => 4[2] => 5[3] => 6)*//* demo2: 不指定截取长度, 则表示从截取开始位置开始, 截取到数组末尾 */$res = array_slice($arr, 9);printfpre($res);/*result:Array([0] => 10[1] => 11[2] => 12)*//* demo3: 保留原索引 */$res = array_slice($arr, 2, 4, true);printfpre($res);/*数组索引还是元素在原数组中的索引Array([2] => 3[3] => 4[4] => 5[5] => 6)*//* demo4: 使用负数值1-从倒数第5个元素开始截取, 截取3个元素, 组成新数组 */$res = array_slice($arr, -5, 3);printfpre($res);/*result:Array([0] => 8[1] => 9[2] => 10)*//* demo5: 使用负数值2-从倒数第5哥元素开始截取, 截取到倒数第2个, 组成新数组, 保留原数组索引 */$res = array_slice($arr, -5, -2, true);printfpre($res);/*result:Array([7] => 8[8] => 9[9] => 10)*/
/* 可以实现对数组元素的：删除，替换/更新，添加 */$arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12];/* demo1: 删除数组中第3个开始, 共4个元素 */$del = array_splice($arr, 2, 4);echobr('被删除的元素:');echobr(implode(', ', $del));echobr('删除元素后的原数组:');echobr(implode(', ', $arr));/*result:被删除的元素:3, 4, 5, 6删除元素后的原数组:1, 2, 7, 8, 9, 10, 11, 12*//* demo2: 不指定截取长度, 表示删除到数组最后一个元素为止 */$arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12];$del = array_splice($arr, 8);echobr('被删除的元素:');echobr(implode(', ', $del));echobr('删除元素后的原数组:');echobr(implode(', ', $arr));/*result:被删除的元素:9, 10, 11, 12删除元素后的原数组:1, 2, 3, 4, 5, 6, 7, 8*//* demo3: 可以使用负数值表示从数组倒数为止开始截取--截取后替换成新的数组元素值 */$arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12];$newElements = ['a', 'b', 'c', 'd'];$del = array_splice($arr, -6, 6, $newElements);echobr('被替换掉的元素:');echobr(implode(', ', $del));echobr('替换元素后的原数组:');echobr(implode(', ', $arr));/*result:被替换掉的元素:7, 8, 9, 10, 11, 12替换元素后的原数组:1, 2, 3, 4, 5, 6, a, b, c, d*//* demo4: 在第5个元素后面插入新的元素(把截取长度设置为0即可) */$arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12];$newElements = ['a', 'b', 'c', 'd'];array_splice($arr, 5, 0, $newElements);echobr('插入新元素后的原数组:');echobr(implode(', ', $arr));/*result:插入新元素后的原数组:1, 2, 3, 4, 5, a, b, c, d, 6, 7, 8, 9, 10, 11, 12*/
/* demo1: 随机从数组中取出一个元素 */$arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12];$res = array_rand($arr);echobr('取出的元素:');echobr($res);/* demo2: 随机从数组中取出多个值 */$res = array_rand($arr, 3);echobr('取出的元素:');echobr(implode(', ', $res));/*result:取出的元素:2, 7, 10*/
说明: 入参2和入参3, 如果待处理的数组是索引数组, 则其值为索引值; 如果待处理数组是关联数组, 则为键名
$arr = [['id' => 1, 'name' => '张三', 'sex' => 'male', 'age' => 25, 'salary' => 9999],['id' => 2, 'name' => '李四', 'sex' => 'female', 'age' => 30, 'salary' => 8888],['id' => 3, 'name' => '王五', 'sex' => 'male', 'age' => 35, 'salary' => 7777],['id' => 4, 'name' => '赵六', 'sex' => 'male', 'age' => 40, 'salary' => 11111],['id' => 5, 'name' => '钱七', 'sex' => 'female', 'age' => 45, 'salary' => 9797],['id' => 6, 'name' => '吴八', 'sex' => 'male', 'age' => 28, 'salary' => 7979],['id' => 7, 'name' => '陈九', 'sex' => 'male', 'age' => 37, 'salary' => 8866],];/* demo1: 取出月薪列的内容, 以name列值作为取出内容的键名 */$res = array_column($arr, 'salary', 'name');printfpre($res);/*result:Array([张三] => 9999[李四] => 8888[王五] => 7777[赵六] => 11111[钱七] => 9797[吴八] => 7979[陈九] => 8866)*//* demo2: 取出第4列值, 以第2列为键名(索引数组才有效) */// $res = array_column($arr, 3, 1);// printfpre($res);/* demo3: 取出年龄列内容 */$res = array_column($arr, 'age');printfpre($res);/*result:Array([0] => 25[1] => 30[2] => 35[3] => 40[4] => 45[5] => 28[6] => 37)*/
替换规则: 用替换数组中的值, 替换原数组中相同键名的元素的值. 当有多个替换数组, 且这些数组中有相同的键名元素时, 后面数组元素值的会覆盖前面的数组元素值
/* demo: */$arr = ['one', 'two', 'three', 'four'];$cover1 = [0 => '1', 4 => '5th'];$cover2 = [0 => 'first'];$res = array_replace($arr, $cover1, $cover2);echobr(implode(', ', $res));/*result: first, two, three, four, 5th*/// array_replace_recursive() 太复杂了, 略.
即, 查找出在所有数组中都出现的键值对(值相等就算, 若值相等键名不等, 则以第一个数组的键名为键名)
$arr = ['first' => '1st', 'second' => '2nd', 'third' => '3rd', 'fourth' => '4th', 'fifth' => '5th'];$intersect1 = ['first' => '1st', 'second' => '第二', 'seventh' => '5th'];$intersect2 = ['first' => '1st', 'second' => '2nd', 'fourth' => '5th'];$res = array_intersect($arr, $intersect1, $intersect2);printfpre($res);/*result:Array([first] => 1st[fifth] => 5th)*/
跟array_interrect()用法一样, 只是array_intersect_assoc()不光要值相等, 键名也要相等才算
$res = array_intersect_assoc($arr, $intersect1, $intersect2);printfpre($res);/*5th值的键名不相等, 所以5th并没有在交集中result:Array([first] => 1st)*/
$arr = ['first' => '1st', 'second' => '2nd', 'third' => '3rd', 'fourth' => '4th', 'fifth' => '5th'];$compare = ['first' => '1st', 'second' => '第二', 'seventh' => '5th'];$res = array_diff($arr, $compare);printfpre($res);/*result:Array([second] => 2nd[third] => 3rd[fourth] => 4th)*/
| 函数名 | 函数功能 |
|---|---|
| current | 获取当前元素的值 |
| key | 获取当前元素的键名 |
| next | 将数组中的内部指针向前移动一位 |
| prev | 将数组内部指针倒回一位 |
| end | 讲数组的内部指针指向最后一个单元 |
| reset | 讲数组的内部指针指向第一个单元 |
$arr = [1, 2, 3, 4, 5, 6, 7, 8, 9];// 获取当前数组指针指向的键名和值echobr('[' . key($arr) . '] => ' . current($arr));/* result: [0] => 1 */// 数组指针向后移动3位(即, 指向第四个元素)next($arr);next($arr);next($arr);echobr('[' . key($arr) . '] => ' . current($arr));/* result: [3] => 4 */// 数组指针往回移一位(即, 指向第三个元素)prev($arr);echobr('[' . key($arr) . '] => ' . current($arr));/* result: [2] => 3 */// 数组指针移到最有一个元素end($arr);echobr('[' . key($arr) . '] => ' . current($arr));/* result: [8] => 9 */// 数组指针重置(指回第一个元素)reset($arr);echobr('[' . key($arr) . '] => ' . current($arr));/* result: [0] => 1 */
$keys = ['name', 'age', 'sex', 'salary'];$values = ['zhangsan', 32, 'male', 8888];$res = array_combine($keys, $values);printfpre($res);/*result:Array([name] => zhangsan[age] => 32[sex] => male[salary] => 8888)*/
/* demo1: 元素键名不全是索引的数组*/$arr = ['host' => 'localhost', 'username' => 'root', 'password' => 'root', 'port' => 3306, 'dbname' => 'phpedu', 0 => 'hello'];$forCombine = ['host' => '127.0.0.1', 'password' => '123456', 0 => 'hi~'];$res = array_merge($arr, $forCombine);printfpre($res);/*注意: 索引值键名并没有被合并, 而是追加到合并数组中(0 => 'hi~')result:Array([host] => 127.0.0.1[username] => root[password] => 123456[port] => 3306[dbname] => phpedu[0] => hello[1] => hi~)*//* demo2: 索引数组 */$arr = [1, 2, 8 => 3, 9 => 4, 10 => 11, 11 => 20];$res = array_merge($arr);printfpre($res);/*数组键名被重排result:Array([0] => 1[1] => 2[2] => 3[3] => 4[4] => 11[5] => 20)*/
$arr = [['id' => 1, 'name' => '张三', 'sex' => 'male', 'age' => 25, 'salary' => 9999],['id' => 2, 'name' => '李四', 'sex' => 'female', 'age' => 30, 'salary' => 8888],['id' => 3, 'name' => '王五', 'sex' => 'male', 'age' => 35, 'salary' => 7777],['id' => 4, 'name' => '赵六', 'sex' => 'male', 'age' => 40, 'salary' => 11111],['id' => 5, 'name' => '钱七', 'sex' => 'female', 'age' => 45, 'salary' => 9797],['id' => 6, 'name' => '吴八', 'sex' => 'male', 'age' => 28, 'salary' => 7979],['id' => 7, 'name' => '陈九', 'sex' => 'male', 'age' => 37, 'salary' => 8866],];/* demo: 模拟分页, 第三个参数默认为false */$pageSize = 2;$data = array_chunk($arr, $pageSize);printfpre($data);/* result: 返回结果是以分割成的数组为元素值的索引数组. 返回结果太长, 结果略.*/
可以是数字, 字母
/* demo1: 从1开始, 每隔3个数, 取一个数值, 直到20 */$arr = range(1, 20, 3);echobr(implode(', ', $arr));/* result: 1, 4, 7, 10, 13, 16, 19 *//* demo2: 从'h'开始, 每隔4个字母, 取一个字母, 直到'z' */$arr = range('h', 'z', 4);echobr(implode(', ', $arr));/* result: h, l, p, t, x */
/* demo1: 索引从5开始, 填充5个元素, 填充值为100 */$arr = array_fill(5, 5, 100);printfpre($arr);/* result:Array([5] => 100[6] => 100[7] => 100[8] => 100[9] => 100)*/
/* demo */$res = array_fill_keys(['key1', 'key2', 'key3', 'key4'], 100);printfpre($res);/*result:Array([key1] => 100[key2] => 100[key3] => 100[key4] => 100)*/
$arr = [1, 2, 3, 4, 5];/* demo1: 向右填充 */$res = array_pad($arr, 10, 100);echobr(implode(', ', $res));/* result: 1, 2, 3, 4, 5, 100, 100, 100, 100, 100 *//* demo1: 向左填充(田崇厚的数组元素总数为负数) */$res = array_pad($arr, -10, 100);printfpre($res);/*填充完成后的键名会重排result:Array([0] => 100[1] => 100[2] => 100[3] => 100[4] => 100[5] => 1[6] => 2[7] => 3[8] => 4[9] => 5)*/
/* demo1: */$userInfo = ['zhangsan', '张三', '男', 34]; //['username' => 'zhangsan', 'realname' => '张三', 'sex' => '男', 'age' => 34];list($username, $realname, $sex, $age) = $userInfo;echobr("用户名: {$username}, 姓名: {$realname}, 性别: {$sex}, 年龄: {$age}");/*result:用户名: zhangsan, 姓名: 张三, 性别: 男, 年龄: 34*//* demo2: PHP7.1+ 支持关联数组 */$arr = [['id' => 1, 'name' => '张三', 'sex' => 'male', 'age' => 25, 'salary' => 9999],['id' => 2, 'name' => '李四', 'sex' => 'female', 'age' => 30, 'salary' => 8888],['id' => 3, 'name' => '王五', 'sex' => 'male', 'age' => 35, 'salary' => 7777],['id' => 4, 'name' => '赵六', 'sex' => 'male', 'age' => 40, 'salary' => 11111],['id' => 5, 'name' => '钱七', 'sex' => 'female', 'age' => 45, 'salary' => 9797],['id' => 6, 'name' => '吴八', 'sex' => 'male', 'age' => 28, 'salary' => 7979],['id' => 7, 'name' => '陈九', 'sex' => 'male', 'age' => 37, 'salary' => 8866],];foreach ($arr as ['id' => $id, 'name' => $name, 'salary' => $salary]) {echobr("id: {$id}, name: {$name}, salary: {$salary}");}/*result:id: 1, name: 张三, salary: 9999id: 2, name: 李四, salary: 8888id: 3, name: 王五, salary: 7777id: 4, name: 赵六, salary: 11111id: 5, name: 钱七, salary: 9797id: 6, name: 吴八, salary: 7979id: 7, name: 陈九, salary: 8866*//* demo3: PHP7.1+ 支持关联数组 */$userInfo = ['username' => 'zhangsan', 'realname' => '张三', 'sex' => '男', 'age' => 34];list('username' => $username, 'age' => $age) = $userInfo;echobr("姓名: {$username}, 年龄: {$age}");/* result: 姓名: zhangsan, 年龄: 34 *//* demo4: 索引数组中只取出其中几个值 */$userInfo = ['zhangsan', '张三', '男', 34];list($username,,, $age) = $userInfo;echobr("姓名: {$username}, 年龄: {$age}");/* result: 姓名: zhangsan, 年龄: 34 */// 另一种写法list(0 => $username, 3 => $age) = $userInfo;echobr("姓名: {$username}, 年龄: {$age}");/* result: 姓名: zhangsan, 年龄: 34 */
$arr = [1, 2, 3, 4, 5, 6];$arrStr = implode(', ', $arr);echobr($arrStr);/* result: 1, 2, 3, 4, 5, 6 */
$arrStr = '1, 2, 3, 4, 5, 6';$arr = explode(', ', $arrStr);dumpbr($arr);/* result: array(6) { [0]=> string(1) "1" [1]=> string(1) "2" [2]=> string(1) "3" [3]=> string(1) "4" [4]=> string(1) "5" [5]=> string(1) "6" } */
$userInfo = ['username1' => 'zhangsan', 'realname1' => '张三', 'sex1' => '男', 'age1' => 34];extract($userInfo);echobr("用户名: {$username1}, 姓名: {$realname1}, 性别: {$sex1}, 年龄: {$age1}");/* result: 用户名: zhangsan, 姓名: 张三, 性别: 男, 年龄: 34 */
/* demo1: */$username = 'lisi';$realname = '李四';$sex = '女';$age = '23';$arr = compact('username', 'realname', 'sex', 'age');printfpre($arr);/* result:Array([username] => lisi[realname] => 李四[sex] => 女[age] => 23)*//* demo2: 也可以把全部或部分变量名以数组的形式传入 */$keys = ['username', 'realname', 'sex', 'age'];$arr1 = compact($keys);printfpre($arr1);/*result:Array([username] => lisi[realname] => 李四[sex] => 女[age] => 23)*/
// 创建一个1-20的数组$arr = range(1, 20);/* demo1: 过滤出所有的偶数元素 */$res = array_filter($arr, function ($val) {if ($val % 2 == 0) {return true;}return false;});// 使用array_merge()函数重排键名$res = array_merge($res);printfpre($res);
/* demo1: 遍历数组, 1000以下不打折; 1000-3000打9折; 3001-5000打8折; 5001以上打7折 */$prices = [888, 1024, 3099, 4799, 5555, 9999];$cutPrices = array_map(function ($price) {switch ($price) {case ($price >= 1000 && $price <= 3000):return $price * 0.9;break;case ($price > 3000 && $price <= 5000):return $price * 0.8;break;case ($price > 5000):return $price * 0.7;break;default:return $price;}}, $prices);printfpre($cutPrices);/*result:Array([0] => 888[1] => 921.6[2] => 2479.2[3] => 3839.2[4] => 3888.5[5] => 6999.3)*//* demo2: 有多个数组的情况-计算面积 */$length = [3, 5, 10];$width = [7, 2, 4];$area = array_map(function ($l, $w) {return $l * $w;}, $length, $width);printfpre($area);/*result:Array([0] => 21[1] => 10[2] => 40)*/
$arr = [1, 2, 3, 4, 5];/* demo1: 所有数组元素乘以x */array_walk($arr, function ($val, $key, $userdata) {echobr("每个元素值将会乘以: {$userdata}");$key += 1;$res = $val * $userdata;echobr("处理第{$key}个元素: {$val} 乘以 {$userdata} 等于 {$res}");echobr();}, 10);/* result:每个元素值将会乘以: 10处理第1个元素: 1 乘以 10 等于 10每个元素值将会乘以: 10处理第2个元素: 2 乘以 10 等于 20每个元素值将会乘以: 10处理第3个元素: 3 乘以 10 等于 30每个元素值将会乘以: 10处理第4个元素: 4 乘以 10 等于 40每个元素值将会乘以: 10处理第5个元素: 5 乘以 10 等于 50*/
天蓬老师