PHP array cheetsheet

PHP array cheetsheet

array_keys: get array keys

• get array keys (取得 array key，成為新的 array)
• $new_array = array_keys($array)
• Ref: https://www.php.net/manual/en/function.array-keys.php

array_flip: flip array key and value

• flip array key and value (把 array key 和 value 互換)
• $flipped = array_flip($input);
• useful when find a value in the array (在找是否含有某數值的時候，特別好用)
• Ref: https://www.php.net/manual/en/function.array-flip.php

array_chunk: split array into chunks

• split array into chunks (把 array 切成數個小 array)
• $new_array = array_chunk($input_array, 2)
• $new_array = array_chunk($input_array, 2, true)
  • true: keep original array key (如果設為 true 表示要保留 array key)
• useful when data updating in batch (在批次匯入大量資料到 db 的時候好用)
• Ref: https://www.php.net/manual/en/function.array-chunk.php

array_column: get specific key value from multidimensional array

• get specific key value from multidimensional array (多層 array，取得每個子層的某個鍵的數值拼成新 array)
• Get the column of first names from a recordset (取每個子層 key 為 first_name 的值，拼成新 array)
  • $first_names = array_column($records, 'first_name');
• Get the column of last names from a recordset, indexed by the “id” column (取每個子層 key 為 first_name 的值，並且新 array key 為 id，拼成新 array)
  • $last_names = array_column($records, 'last_name', 'id');
• Ref: https://www.php.net/manual/en/function.array-column.php

array_combine: creates an array by using one array for keys and another for its values

• creates an array by using one array for keys and another for its values (組合成對的兩個 array 成為新的 array，一個陣列為 key，一個陣列為 value)
• $c = array_combine($key_array, $value_array);
• Ref: https://www.php.net/manual/en/function.array-combine.php
• https://stockwfj3.pixnet.net/blog/post/46322454

array_search: find if the value in the array (尋找 array 是否有這個數值，有的話回傳 key)

• $key = array_search('value', $array);
• Ref: https://www.php.net/manual/en/function.array-search