String Object

1. Concatinate:

   When one object you are adding is a string, then the items are concatinated together. For example when adding two strings, they are concatinated.

   stuff = "this is some stuff";
   moreStuff = " here is more stuff";
   answer = stuff + moreStuff // answer = "this is some stuff here is more stuff"
   

   The same is true if one object is a string and the other a number. The two will be concatinated.

   item = "The number of tennis balls I have :";
   count=3;
   answer = item+count		//answer = "The number of tennis balls I have :3"
   

2. Convert to a string

   Sometimes you want to perform string methods on a number or a date. Before you can do that you need to convert the number to a string, otherwise you will get javaScript error. In the following function I wanted to split the dollars from the cents at the decimal place. Using the split method of the string object works great, however first you have to convert the number to a string.

   function fix(numToFix, decimalPlaces){
   if(isNaN(fixNumber)) 	return 0;
   var div = Math.pow(10, decimalPlaces);	
   numToFix = Math.round(numToFix * div)/div;	
   var string = numToFix.toString();	//convert the number to a string variable
   	var parts = string.split(".");	//split at the decimal
   	var cents = parts[1];		//(dollars in one part,cents in the other)
   	while (cents.length<decimalPlaces)	//add as many zeros as needed
   	     cents += "0";
   	return parts[0]+"."+cents	//return the formatted number
   }

   click here to see the demo
3. Sting Methods

   Sting methods that change the style:

   ---

   Find the position within the string of a word or character.
   substring and indexOf are used quite a bit with cookies.

   ---

   str.replace(regexp, replacement) - replace substring(s) matching a regular expression
   
   var str="Visit Microsoft!"
   document.write(str.replace(/Microsoft/,"Techinmotion"))
   

   ---

   str.split(delimiter, limit)   - Splits a string at the delimiter into an array of strings
   
   arrShipTo = strShipTo.split("~"); //splits strShipTo at each "~" into an array arrShipTo
   

   ---

   click here for a complete list of string methods

   
   
   
4. Practical Examples

• The example below takes address information from a drop down list, and formats the output to a form

  function GetShipTo(strShipToSelected){
  	var arrShipTo=new Array()
  	arrShipTo = strShipToSelected.split("~");
  
  	document.forms[0].txtShipToName.value=arrShipTo[0];
  	document.forms[0].txtShipToAddress1.value=arrShipTo[1];	
  	document.forms[0].txtShipToAddress2.value=arrShipTo[2];	
  	document.forms[0].txtShipToAddress3.value=arrShipTo[3];	
  	document.forms[0].txtShipToAddress4.value=arrShipTo[4];	
  	document.forms[0].txtShipToCountry.value=arrShipTo[5];		
  	document.forms[0].txtShipToCity.value=arrShipTo[6];		
  	document.forms[0].txtShipToState.value = arrShipTo[7];
  	document.forms[0].txtShipToZip1.value=arrShipTo[8];
  }
  

  click here to see the example
  
  

• This example receives a texarea object and the max number of characters the user can type in. If the user types more than the max characters, the text is truncated

  function checkTextAreaLength(theTextarea, maxLength){
  if (theTextarea.value.length > maxLength){
  		alert("You have reached the" + maxLength + " character limit.") ;
  		theTextarea.value = theTextarea.value.substring(0,maxLength) ;
  		theTextarea.focus();}
  }

  click here to see the demo