Methods and Functions

One of the strengths of JScript is that a lot of the difficult work has been done for you, with methods and functions covering a wide range of functionality. From performing calculations to manipulating dates and strings, JScript has a method or function to suit you.

Conversion Functions

Since JScript variables can be of many different types, there are a couple of conversion functions you will be using often if you want to ensure that a particular field value is either an integer or floating decimal point number. These conversion functions are listed in Table B-4.

Table B-4: Conversion Functions

Operator	Description	Example Usage
parseInt	For parsing other variable types to integer	parseInt(Quantity);
parseFloat	For parsing other variable types to a floating decimal point number	parseFloat(OrderTotal);

String Functions

String functions within JScript treat strings like an array and can be used to find substrings within a string, change the case of a string, concatenate two strings, and more. Table B-5 lists and describes the string functions.

Table B-5: String Functions

Function	Description	Usage
charAt	Used to return a character at a certain position within a string.	String.charAt(position); MyString.charAt(2); “David”.charAt(3); Returns “v”
indexOf	Used to return the position at which a substring exists within a string, searching from left to right. Can also specify a second argument as a starting point.	String.indexOf(substring); MyString.indexOf(“Sales”); MyString.indexOf(“al”,2); ”David”.indexOf(“vi”); Returns 3
lastIndexOf	Used to return the position at which a substring exists within a string, searching from right to left. Can also specify a second argument as a starting point.	String.indexOf(substring); MyString.indexOf(“Market”); MyString.indexOf(“ke”,2); ”Mack”.indexOf(“ack”); Returns 2
split	Can be used to split a string into substrings using a delimiter (spaces, and so on) and put the resulting substrings into an array.	String.split(“ “); MyString.split(“,”); “My old dog”.split(“ “);
toLowerCase	Used to convert a string to lowercase.	String.toLowerCase(); MyString.toLowerCase(); “David”.toLowerCase();
toUpperCase	User to convert a string to uppercase.	String.toUpperCase(); MyString.toUpperCase(); “Mack”.toUpperCase();
length	Used to determine the length of a string.	String.length; MyString.Length; “David Mack”.Length;

Date and Time Functions

The date and time functions within JScript are easy to use and provide methods to pull apart a date and work with the components. All the examples in Table B-6, which lists the date and time functions, assume that the variable InvoiceDate is a date-time field with a value of 12/11/2003 8:10:57 AM.

Table B-6: Date and Time Functions

Function	Description	Example Usage
getDate	Returns the day-of-month value (1 to 31) from a date field	InvoiceDate.getDate() Returns 11
getDay	Returns the day of the week, where: 0 = Sunday 1 = Monday 2 = Tuesday 3 = Wednesday 4 = Thursday 5 = Friday 6 = Saturday	InvoiceDate.getDay() Returns 4
getFullYear	Returns the full year from a date field	InvoiceDate.getFullYear() Returns 2003
getHours	Returns the hours value from a date field	InvoiceDate.getHours() Returns 8
getMinutes	Returns the minutes value from a date field	InvoiceDate.getMinutes() Returns 10
getMonth	Returns the month value from a date field, where: 0 = January 1= February 2 = March 3 = April 4 = May 5 = June 6 = July 7 = August 8 = September 9 = October 10 = November 11 = December	InvoiceDate.getMonth() Returns 11
getSeconds	Returns the seconds value from a date field	InvoiceDate.getSeconds() Returns 57
getTime	Returns an integer value representing the number of milliseconds between midnight, January 1, 1970 and the time value in the Date object	InvoiceDate.getTime() Returns 1071090659513
getYear	Returns the year value from a date field	InvoiceDate.getYear() Returns 2003

Array Functions

Arrays can easily be created in JScript by a simple declaration. And then any array elements can be referenced using square brackets []. Arrays in JScript are zero-based, so the first element will always be 0, as shown in the following example:

var myArray = new Array();
for (i = 0; i < 10; i++)
    {
    myArray[i] = i;
    }