# Understand formula field's expression

The formula field's Expression is what defines the value it will store and display. For example, the Amount field in an Order form is usually a result of multiplying the values in Unit Price and ​Ordered Quantity fields. The expression of this Amount field will be:

Unit_Price * Ordered_Quantity

Here Unit_Price and Ordered_Quantity are field link names and the asterisk (*) represents the arithmetic operator that multiplies the values in the two fields. Refer to the following sections to learn about defining a formula field's expression:

## Building blocks of expressions

A formula field's expression can be a combination of the following:

 Fields The expression can include fields in same form and fields in related forms (related via lookup and subform fields) Constants They refer to static values. A constant can be some text, number, special character, or a combination of these. For example, abcd is a string constant, 123.02 is a numeric constant, abcd - 123 is a string constant (even though it contains the number 123). A constant's data type is determined by the manner in which it's included in the expression. Refer to the guidelines Deluge system variables Including Deluge system variables can come in handy. For example, zoho.currentdate is a variable that returns the current date. Learn more Operators These are symbols that perform specific computations on one or more values (referred to as 'operands'). For example, the + symbol is an arithmetic operator that performs the addition of two numbers or concatenation of two strings. Learn more Built-in functions They perform specific operations on one or more values. For example, the length() function returns the number of characters present in a string. Learn more

## Guidelines for defining expressions

The sample expressions section illustrates these guidelines.

• With regard to including fields in expressions:
• Fields are to be referred by their field link names. Expressions can include all types of field except add notes and section. A formula field can be referred in the expression of another formula field.
• To include Deluge system variables, you must type them.
• With regard to including constants in expressions:
• String constants are to be enclosed within double quotation marks. Numeric constants are to be added as such. Date and date-time constants are to be enclosed within single quotation marks.
• Parentheses are to be added to define the order of execution (while evaluating the expression)
• Example 1: The result of the expression 2 + 3 * 5 will be 17. The multiplication operator (*) has precedence of execution over the addition operator (+). So 3 and 5 will be multiplied first, and then their result (15) will be added with 2.
• Example 2: The result of the expression (2 + 3) * 5 will be 25. The parentheses ensures that the operation within it is executed first. So first 2 and 3 will be added, and then their result (5) will be multiplied with 5.

## Defining conditional expressions

A conditional expression is one that returns one of two values subject to the result of a boolean expression. It's defined as follows:
if ( <condition>, <value if the condition is true>, <value if the condition is false> )

Let's take an example. Imagine that you want to discount the Amount in an Orders form by \$10 if the ordered quantity exceeds 15. (To keep it simple, it is assumed here that an order can include only one product. This is mostly not the case in the real world.)

• The condition here is if the quantity that's requested in an order is greater than 15 or not
• If the ordered quantity is greater than 15, the expression is to return a discouted value
• If the ordered quantity is 15 or less, the expression is to return the amount as such
This expression will be as follows:
if ( Ordered_Quantity > 15, Amount - 100, Amount )

You can nest conditional expressions — use one conditional expression inside another. Refer to this section to see a sample expression.

## Sample expressions

### Expressions including constants and Deluge system variables

 Purpose of Formula field Its Expression Explanation Display a string "abcd" String values must be enclosed within double quotation marks Display a string that contains double quotation marks, say "\"abcd\"" Backslash character (\) must precede the double quotation marks you want to display Display a number 105 Numbers can be inserted as such Display a decimal value 105.23 Decimal values can be inserted as such Display a date value '10-Aug-2018' Date values are to be enclosed with single quotation marks. The value must follow the date format set in that app's Settings. (This example considers the format to be dd-MMM-yyyy) Display the current date zoho.currentdate or today zoho.currentdate and today are system variables that return the current date Display tomorrow's date tomorrow or today.addDay(1) tomorrow is a system variable that returns the date of the day after the current day. addDay() is a built-in date function. Display yesterday's date yesterday yesterday is a system variable that returns the date of the day before current day Display a date-time value '10-Aug-2018 14:30:00' Date-time values are to be enclosed with single quotation marks. The value must follow the date format set in that app's Settings. This example considers the format to be dd-MMM-yyyy. Display the current date and time zoho.currenttime or now zoho.currenttime and now are system variabes that return the current date and time Round off a decimal value to nearest hundredth, i.e., 2 digits after the decimal point 10.5356.round(2) or 100.2345.round(2) round() is a built-in function. It requires you to tell what value it is to operate on, and the number of decimal places it is to round the decimal value to. Find the number of characters in a string "This is a string".length() length() is a built-in function. It returns the number of characters present in a string, including whitespaces. Find the number of days between the entered date and current date zoho.currentdate.daysBetween(Delivery_Date) zoho.currentdate is the system variable that returns the current date. Delivery_date is a field link name. daysBetween() is a built-in function that returns the number of days between two date or date-time values.

### Expressions including lookup and subform fields

 Purpose of Formula field Its Expression Explanation Display the Email Alias of the Department in which the Employee works Department.Email_Alias Usually an employee would be assigned to only one department at a time. This relationship is established using the lookup field. Department data is looked-up from the Employees form. Department and Email_Alias are the field link names. Display the Price of a Product when placing orders Product.Price Usually product details are stored in a separete form, and are looked-up in the Order form. Product is the lookup field added to the Order form, through which the selected product's Price is fetched. Display the Line Total of each ordered product in an Orders form Price * Quantity Price and Quantity are field link names. Price can be a formula field that displays the selected product's price from the Product form. (see the example above) Display the number of records added in the subform Line_Items.count() Line_Items is the field link name of the subform. count() is a built-in aggregation function that returns the number of records in a form. Display in the main form the sum of numeric values present in the subform Line_Items.sum(Line_Total) Line_Items is the field link name of the subform. Line_Total is the link name of the field that stores the line total (see the example above) of each ordered product. sum() is a built-in aggregation function.

### Conditional expressions

Refer to this section to learn what a conditional expression is.

 Purpose of Formula field Condition Value if condition holds true Value if condition doesn't hold true Final expression Explanation When user has selected a product and entered a quantity in an Orders​ form, set its Line Total with the product (multiplication) of its Price and Quantity, else set it as zero (0). Product.Price != null && Quantity != null Product.Price * Quantity 0 if(Product.Price != null && Quantity != null, Product.Price * Quantity, 0) Price and Quantity are field link names. Price can be a formula field that displays the selected product's price from the Product form. Convert the numerical Rating your users selects in your Webinar Feedback form, into a word: 1 - Poor, 2 - Average, 3 - Good, 4 - Excellent. These numerical values would be choices displayed by a radio field. Rating == "1" "Poor" if(Rating == "2", "Average", if(Rating == "3", "Good", "Excellent")) if(Rating == "1", "Poor", if(Rating == "2", "Average", if(Rating == "3", "Good", "Excellent"))) This is an example of nesting conditional expressions. Rating is the link name of the choice field, with 1, 2, 3, and 4 as its choices. The expression progressively checks from 1 to 4, and returns the corresponding word.