Grep regex to ignore sequence only if surrounded by fwd-slashes Post: 302878742

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Top Forums Shell Programming and Scripting Grep regex to ignore sequence only if surrounded by fwd-slashes Post 302878742 by Chubler_XL on Sunday 8th of December 2013 03:41:58 PM

12-08-2013

Moderator

Quote:

Originally Posted by gencon

But I am concerned with:

"NOTE: A reference to an element that does not exist automatically creates that array element, with the null string as its value."

and...

"Array elements can be assigned values just like awk variables:
array[index-expression] = value"

Nothing saying: "if no assignment is made then the value of index-expression is assigned as the value of the element..."

The code ipUnique[ip] = ip; and ipUnique[ip]; are not equivalent.

The first creates array element ip with a null value (if it doesn't already exist) and then assigns it's value to ip.

The second creates array element ip with a value of null only.

The reason the replacement works is the code never uses the value of the array element and this is irrelevant. It could be 1, NULL or equal to the index and the code still works as intended.

Here is a small example that might help to illustrate.

Code:

$ awk 'BEGIN {
   A[1];A[2];A[3]=3;
   delete A[2];
   for(idx=0;idx<4;idx++)
      printf("A[%d]=%s\n", idx,
         (idx in A) ? (A[idx] == "" ? "Null" : A[idx]) : "Undefined"); }'
A[0]=Undefined
A[1]=Null
A[2]=Undefined
A[3]=3

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LEARN ABOUT PHP

array_pop

ARRAY_POP(3)								 1							      ARRAY_POP(3)

array_pop - Pop the element off the end of array

SYNOPSIS

       mixed array_pop (array  &$array)

DESCRIPTION

       array_pop(3) pops and returns the last value of the $array, shortening the $array by one element.

       Note

	      This function will reset(3) the array pointer of the input array after use.

PARAMETERS

	      o $array
		- The array to get the value from.

RETURN VALUES

	Returns the last value of $array. If $array is empty (or is not an array), NULL will be returned.

ERRORS
/EXCEPTIONS
	This function will produce an error of level  E_WARNING when called on a non-array.

EXAMPLES

       Example #1

	      array_pop(3) example

	      <?php
	      $stack = array("orange", "banana", "apple", "raspberry");
	      $fruit = array_pop($stack);
	      print_r($stack);
	      ?>

	       After this, $stack will have only 3 elements:

	      Array
	      (
		  [0] => orange
		  [1] => banana
		  [2] => apple
	      )

	       and raspberry will be assigned to $fruit.

SEE ALSO

       array_push(3), array_shift(3), array_unshift(3).

PHP Documentation Group 													      ARRAY_POP(3)

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