Generate Random String

function generateRandomString(strlen:Number):String{
  var chars:String = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
  var num_chars:Number = chars.length - 1;
  var randomChar:String = "";
 
  for (var i:Number = 0; i < strlen; i++){
  randomChar += chars.charAt(Math.floor(Math.random() * num_chars));
  }
  return randomChar;
}
trace(generateRandomString(7));

Convert String To Number

var str:String = "10";
var num:Number = Number(str);

Removes Whitespace From String

var str:String = "action script";

function removeWhiteSpace(str:String):String {
 var newstring = str.split(" ").join("");
 return newstring;
}

trace(removeWhiteSpace(str)); //Outputs actionscript

Count All Occurrences of a Character In a String

var str:String = "programmer";
var char:String = "m";

function countOccurences(str:String, char:String):Number {
 var count:Number = 0;
 
 for(var i=0; i < str.length; i++) {
  if (str.charAt(i) == char) {
   count++;
  }
 }
 return count;
}

trace(countOccurences(str, char)); //Outputs 2

Capitalize First Letter In String

var str = "actionscript";

function upperCase(str:String) : String {
 var firstChar:String = str.substr(0, 1); 
 var restOfString:String = str.substr(1, str.length); 
    
 return firstChar.toUpperCase()+restOfString.toLowerCase(); 
}

trace(upperCase(str)); //Outputs Actionscript

Search And Replace Characters In String

Simple solution for replacing characters in a string

var str:String = "AS3 rocks!";
var search:String = "AS3";
var replace:String = "Actionscript 3";

function strReplace(str:String, search:String, replace:String):String {
 return str.split(search).join(replace);
}

trace(strReplace(str, search, replace)); //Outputs Actionscript 3 rocks!

Reverse A String

var myString:String = "reverse";

trace(myString.split("").reverse().join("")); //Output - esrever

Email Validation

Function that validates email.

function isValidEmail(email:String):Boolean {   
 var emailExp:RegExp = /^[a-z][\w.-]+@\w[\w.-]+\.[\w.-]*[a-z][a-z]$/i;           
    return emailExp.test(email);     
 } 

trace(isValidEmail("admin@domain.com")); //Outputs true
trace(isValidEmail("admin.@.com")); //Outputs false