Php method for obtaining the value of the first array element in an array element

Reset (PHP 3, PHP 4, PHP 5)

Function definition mixed reset (array & array)

Function: returns the internal pointer of array to the first unit and the value of the first array unit. If the array is null, FALSE is returned. For example:

 

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<? Php $ Array = array ('step one', 'step two', 'step three ', 'step four '); Echo reset ($ array );

// Output: step one
Next (PHP 3, PHP 4, PHP 5)

Function definition mixed next (array & array)

Purpose: return the value of the next unit pointed to by the internal pointer of the array, or FALSE if no more units exist. For example:

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<? Php $ Array = array ('step one', 'step two', 'WWW ', 'phpernote. Com', 'step four '); Echo next ($ array );

// Output: step two
Warning if the array contains an empty unit or the unit value is 0, FALSE is returned when this function encounters these units. To correctly traverse arrays that may contain null cells or whose unit value is 0, see the each () function.

Current (PHP 3, PHP 4, PHP 5)

Function definition mixed current (array & array)

Purpose: return the value of the array unit pointed to by the internal pointer, without moving the pointer. Initially point to the first unit inserted into the array. If the internal pointer points to an end that exceeds the cell List, current () returns FALSE.

Warning if the array contains an empty unit (0 or "", null string), this function returns FALSE when this unit is encountered. This makes it impossible to use current () to determine whether it has reached the end of the array list. To traverse arrays that may contain null cells correctly, use the each () function.

The behavior of next () and current () is similar. There is only one difference. Before returning the value, move the internal pointer one byte forward. This means that it returns the value of the next array unit and moves the array pointer one bit forward. If the result of moving the pointer exceeds the end of the array unit, next () returns FALSE.

The following is an example of using related functions:

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<? Php $ Transport = array ('foot', 'WWW ', 'car', 'phpernote', 'com '); $ Mode = current ($ transport); // $ mode = 'foot '; $ Mode = next ($ transport); // $ mode = 'WWW '; $ Mode = next ($ transport); // $ mode = 'car '; $ Mode = prev ($ transport); // $ mode = 'WWW '; $ Mode = end ($ transport); // $ mode = 'com '; $ Mode = current ($ transport); // $ mode = 'com '; $ Mode = reset ($ transport); // $ mode = 'foot ';