PHP Arrays

<?php /* ARRAY INITIALIZATION * =============================================== */ $fruits = array(); $fruits = array( 'apples', 'avocados', 'oranges', 'bananas' ); $veggies = array( 'broccoli' => 1, 'lettuce' => 5, 'celery' => 0, 'spinach' => 5 ); $food = array( $fruits, $veggies ); $multi = array( array( 'foo' => 'bar' ), array( 'x' => 'y' ), 'key' => 'value', 3, 2, 1 ); /* ARRAY CHECKS * =============================================== */ $a = array(); is_array( $a ); // true is_array( "string" ); // false empty( $a ); // true count( $a ); // 0 sizeof( $a ); // 0 $a = array(1, true, 'hello'); var_dump ( $a ); // array(3) { [0]=> int(1) [1]=> bool(true) [2]=> string(5) "hello" } print_r ( $a ); // Array ( [0] => 1 [1] => 1 [2] => hello ) /* ARRAY ACCESS * =============================================== */ $fruits[ 0 ]; // 'apples' $veggies[ 'lettuce' ]; // 5 list ( $first_item, $second_item ) = $fruits; $vars = array ( 'a' => 123 ); extract( $vars ); // unsafe for untrusted data echo $a; // 123 /* ADD * =============================================== */ $fruits[] = 'apples'; // add to end $veggies [ 'potato' ] = 3; array_unshift( $fruits, "raspberries", "blueberries" ); // add to beginning array_push( $fruits, "raspberries", "blueberries" ); // add to end $x = 1; $y = 2; $z = 3; $vars = compact ( "x", array ( "y", "z" ), "random" ); print_r ( $vars ); // Array ( [x] => 1 [y] => 2 [z] => 3 ) /* MERGE * =============================================== */ $colors = array( 'green', 'red', 'yellow' ); $food = array( 'avocado', 'apple', 'banana' ); $colored_food = array_combine( $colors, $food ); // keys + values $result = array_merge( $fruits, $veggies ); // 2nd array overrides 1st array, numbers are appended $base = array( "orange", "banana", "apple", "raspberry" ); $replacements = array( 0 => "pineapple", 4 => "cherry" ); $replacements2 = array( 0 => "grape" ); $basket = array_replace( $base, $replacements, $replacements2 ); // keys are replaced or created /* REMOVE * =============================================== */ $fruit = array_shift( $fruits ); // remove item from begining $fruit = array_pop( $fruits ); // remove item from end unset( $fruits [ 'apples' ] ); $a = array( 1, 2, 3, NULL, "", "text", 4, 5 ); $a = array_filter( $a ); // removes empty and null values $a = array_filter( $a, 'is_numeric' ); // returns only numeric values /* FOR LOOPS * =============================================== */ // loop through each item foreach ( $fruits as $fruit ) { echo "fruit: $fruit \n"; } // loop through each item with index foreach ( $fruits as $inx => $fruit ) { echo "$inx. fruit: $fruit \n"; } $max = count( $fruits ); for ( $i = 0; $i < $max; $i ++ ) { if ( $i === 0 ) { continue; } // advance loop echo $fruits [ $i ]; if ( $i === 3 ) { break; } // stop loop } /* DO WHILE LOOP * =============================================== */ $i = 10; do { echo $i; } while ( $i-- ); /* ARRAY CONVERSION * =============================================== */ // convert to string $fruits_str = implode( ',', $fruits ); // convert string to array $fruits = explode( ',', $fruits_str );