Designer has built-in operators that can be used in enabling conditions or validations. This article explains the following operators that you can use in your instrument:
Arithmetic Operators
The following table shows the arithmetic operators supported by Survey Solutions. Arithmetic expressions are evaluated from left to right. For the example, assume A = 20 and B = 10
| Operator | Description | Example |
|---|---|---|
| + | Addition: returns the sum | A + B = 35 |
| - | Subtraction: returns the difference | A - B = 10 |
| * | Multiplication: returns the product | A * B = 200 |
| / | Division: returns the quotient | B / A = 2 |
| % | Modulus: returns the remainder after an integer division | B % A = 0 (The remainder of 20 divided by 10 is 0) |
Relational Operators
These operators compare two values and return either TRUE or
FALSE. The following comparison operators are supported by Survey
Solutions:
| Operator | Description | Example |
|---|---|---|
| == | Checks if the two values are equal. If values are equal, then the condition is true | 20 == 10 returns FALSE |
| != | Checks if the two values are not equal. If the values are not equal, then the condition is false | 20 != 10 returns TRUE |
| > | Checks if the left value is greater than the right value | 20 > 10 returns TRUE |
| < | Checks if the left value is less than the right value | 20 < 10 returns FALSE |
| >= | Checks if the left value is greater than or equal to the right value | 20 >= 10 returns TRUE. 10 >= 10 returns TRUE. |
| <= | Checks if the left value is less than or equal to the right value | 20 <= 10 returns FALSE. 10 <= 10 returns TRUE. |
Logical Operators
Logical values returns either TRUE or FALSE. The following tables show the logical operators supported by Survey Solutions:
| Operator | Description | Example |
|---|---|---|
| && | Logical AND operator. A && B returns true of both expression A and B are true. | (20 == 10) && (10 > 5) returns FALSE (10 == 10) && (10 > 5) returns TRUE |
| || | Logical OR operator A || B returns true if either expression A or expression B is true | (20 == 10) || (10 > 5) returns TRUE (20 == 10) || (10 < 5) returns FALSE |
| ! | Logical NOT operator !A returns true if expression A is false. It returns false if expression A is true. | !(20 == 10) returns TRUE !(10 == 10) returns FALSE |
Other Useful Operators
These are other operators that you might want to use in your Survey Solutions instrument.
| Operator | Description | Example |
|---|---|---|
| ?: | Conditional Expression/ The condition must evaluate to true or false. If condition is true, the first expression is evaluated and becomes the result. If condition is false, the second expression is evaluated and becomes the result. Only one of the two expressions is evaluated. | (10 < 2)? a:b will return b (10 > 2)? a:b will return a |