31.) what is the use of rand() in php?
It is used to generate random numbers.If called without the arguments it returns a pseudo-random integer between 0 and getrandmax(). If you want a random number between 6 and 12 (inclusive), for example, use rand(6, 12).This function does not generate cryptographically safe values, and should not be used for cryptographic uses. If you want a cryptographically secure value, consider using openssl_random_pseudo_bytes() instead.
32.) How to find the length of a string?
strlen() function used to find the length of a string
33.) what is the use of isset() in php?
This function is used to determine if a variable is set and is not NULL
34.) How to set a page as a home page in a php based site ?
index.php is the default name of the home page in php based sites
35.) What is the difference between mysql_fetch_array() and mysql_fetch_assoc() ?
mysql_fetch_assoc function Fetch a result row as an associative array, Whilemysql_fetch_array() fetches an associative array, a numeric array, or both