Question:What is the difference between sizeof($array) and count($array)? 

sizeof($array) - This function is an alias of count()
count($array) - If you just pass a simple variable instead of an array it will return 1.

Question:What are the different functions in sorting an array? Discuss them?

 

array_reverse():    reverses an array’s element order.

array_flip(): reverses the roles of the keys and their corresponding values.
    
sort(): sorts an array, ordering elements from lowest to highest value.

rsort(): sorts array items in reverse (descending) order.

asort() : sorting an array in ascending order, except that the key/value correspondence is maintained.

arsort(): it sorts the array in reverse order maintained key/value co-relation.

Question:Why substr() is used?

 

The substr() function returns the part of a string located between a predefined starting offset and length positions.

Its prototype : string substr(string str, int start [, int length])

Question:Difference between array_merge() and array_slice()?

 

Array_merge():The array_merge() function merges arrays together, returning a single, unified array.

Array_slice(): The array_slice() function returns a section of an array based on a starting and ending offset value.

Question:Difference between array_merge() and array_slice()?  

Ans: The array_merge() function merges one or more arrays into one array. This function returns one array with the elements of all the parameter arrays.

The array_slice() function returns selected parts of an array. The array_slice() function returns part of an array as specified by the start and length parameters. If start is a positive number, it means that the ”slice” will start that many elements from the beginning of the array.

Question:How can we automatically escape incoming data? 

We have to enable the Magic quotes entry in the configuration file of PHP.