1.Math expression eval object initialization

Afe_Evaluator expr = new Afe_Evaluator('IF(abc>1,"passed","fail")');

or using default constructor + setExpression() method:

Afe_Evaluator expr = new Afe_Evaluator();
expr.setExpression('IF(abc>1,"passed","fail")');

2.Bind variable

Afe_Evaluator expr = new Afe_Evaluator('IF(abc>1,"passed","fail")');
expr.bind('abc',2);

3. Eval the expression

//Class initialization
Afe_Evaluator expr = new Afe_Evaluator('IF(abc>1,"passed","fail")');
//Bind variable
expr.bind('abc',2);
//eval
expr.eval(); // return "passed"

Result:

4. Multiple methods on one line

new Afe_Evaluator('IF(abc>1,"passed","fail")').bind('abc',2).eval();

5. Conditional statements

IF/ELSE condition:

//Class initialization
Afe_Evaluator expr = new Afe_Evaluator('IF(OR(AND(abc>1, def<100),AND(abc < 1, abc > 0)),"passed","fail")');
//Bind variable
expr.bind('abc',2);
expr.bind('def',99);
//eval
expr.eval(); // return "passed"

SWITCH/CASE condition:

//Class initialization
Afe_Evaluator expr = new Afe_Evaluator('SWITCH(abc,1,"apple",2,"mango",3,"banana","N/A")');
//Bind variable
expr.bind('abc',2);
System.debug(expr.eval()); //return "mango"

6. Set rounding mode and decimal precision

Use setScale() method to set number of digits to the right of the decimal point. Use setRoundingMode() method to set rounding mode. For salesforce apex language, you can use 5 mode as below:

• RoundingMode.CEILING
• RoundingMode.DOWN
• RoundingMode.FLOOR
• RoundingMode.HALF_DOWN
• RoundingMode.HALF_EVEN
• RoundingMode.HALF_UP
• RoundingMode.UP

Afe_Evaluator expr = new Afe_Evaluator('10/3');
//Set scale
expr.setScale(2);
//Set rounding mode
expr.setRoundingMode(RoundingMode.UP);
//eval
System.debug(expr.eval()); // will return 3.34

7. Work with number expression

Example 1: Simple expression

Afe_Evaluator expr = new Afe_Evaluator('(a+b+c)/2');
expr.bind('a',2);
expr.bind('b',3);
expr.bind('c',16);
expr.eval(); // return 10.5

Example 2: Complex expression

Afe_Evaluator expr = new Afe_Evaluator('(a^2+b^2+sqrt(c))%5');
expr.bind('a',2);
expr.bind('b',3);
expr.bind('c',16);
expr.eval(); // return 2

Example 3: Min, max

Afe_Evaluator expr = new Afe_Evaluator('MIN(a,b,c)');
expr.bind('a',2);
expr.bind('b',3);
expr.bind('c',16);
expr.eval(); // return 2

Example 4: Min, max with collection variable

Afe_Evaluator expr = new Afe_Evaluator('MAX(a)');
expr.bind('a',new List<Decimal>{10, 9.6, 135, 724.2, 6, -4});
expr.eval(); // return 724.2

Example 5: Sum, average

Afe_Evaluator expr = new Afe_Evaluator('SUM(a,b,c)');
expr.bind('a',2);
expr.bind('b',3);
expr.bind('c',16);
expr.eval(); // return 21
expr.setExpression('AVERAGE(a,b,c)');
expr.eval(); // return 7

Example 6: Sum, average using collection variable

Afe_Evaluator expr = new Afe_Evaluator('SUM(a)');
expr.bind('a',new List<Decimal>{2, 3, 16});
expr.eval(); // return 21
expr.setExpression('AVERAGE(a)');
expr.eval(); // return 7

Example 7: Round, Floor, Ceiling

Afe_Evaluator expr = new Afe_Evaluator('ROUND(2.149, 1)');
System.debug(expr.eval()); //return 2.1

Afe_Evaluator expr = new Afe_Evaluator('FLOOR(2.149)');
System.debug(expr.eval()); //return 2

//Rounds 3.7 down to nearest multiple of 2
Afe_Evaluator expr = new Afe_Evaluator('FLOOR(3.7,2)');
System.debug(expr.eval()); //return 2

Afe_Evaluator expr = new Afe_Evaluator('CEILING(2.149)');
System.debug(expr.eval()); //return 3

//Rounds 1.5 up to the nearest multiple of 0.1
Afe_Evaluator expr = new Afe_Evaluator('CEILING(1.5, 0.1)');
System.debug(expr.eval()); //return 1.5

Example 8: Trigonometry calculation

Afe_Evaluator expr = new Afe_Evaluator('SIN(PI())^2+COS(PI())^2');
System.debug(expr.eval()); //return 1

Example 9: Unary operator

Afe_Evaluator expr = new Afe_Evaluator('3--2+--3-(-(++2))');
System.debug(expr.eval()); //return 10

8. Work with string

Example 1:

Afe_Evaluator expr = new Afe_Evaluator('IF(LEFT(abc,4)="2021","n/a","generation of " & LEFT(abc,4))');
expr.bind('abc','2022-01-20');
System.debug(expr.eval());

9. Work with datetime

Example 1: Calculate networkday

Afe_Evaluator expr = new Afe_Evaluator('NETWORKDAYS(DATEVALUE("2021-03-30"),DATEVALUE("2022-05-16"))');
System.debug(expr.eval()); // return 295

Afe_Evaluator expr = new Afe_Evaluator('NETWORKDAYS(startdate,enddate)');
expr.bind('startdate', Date.newInstance(2021,08,11));
expr.bind('enddate', Date.newInstance(2021,10,4));
System.debug(expr.eval()); // return 39

Example 2: Calculates the number of days, months, or years between two dates.

Afe_Evaluator expr = new Afe_Evaluator('DATEDIF(DATEVALUE("2021-01-31"),DATEVALUE("2029-08-29"),"Y")');
System.debug(expr.eval()); // return 8

Afe_Evaluator expr = new Afe_Evaluator('DATEDIF(DATEVALUE("2021-01-31"),DATEVALUE("2029-08-29"),"M")');
System.debug(expr.eval()); // return 102

Afe_Evaluator expr = new Afe_Evaluator('DATEDIF(DATEVALUE("2021-01-31"),DATEVALUE("2029-08-29"),"D")');
System.debug(expr.eval()); // return 3132

Afe_Evaluator expr = new Afe_Evaluator('DATEDIF(DATEVALUE("2021-01-31"),DATEVALUE("2029-08-29"),"MD")');
System.debug(expr.eval()); // return 29

Example: Substract, add datetime

Afe_Evaluator expr = new Afe_Evaluator('DATETIME(2021,2,28,15,50,0)-DATETIME(2021,2,21,23,0,0)');
System.debug(expr.eval()); // return 6.70139 (days)

Afe_Evaluator expr = new Afe_Evaluator('DATE(2021,2,28)-DATE(2021,2,21)');
System.debug(expr.eval()); // return 7 (days)

Afe_Evaluator expr = new Afe_Evaluator('DATE(2021,9,20)+3');
System.debug(expr.eval()); // return 2021-09-23

Afe_Evaluator expr = new Afe_Evaluator('TIME(10,10,0)+TIME(10,10,0)');
System.debug(expr.eval()); // return 20:20:00

10. Complex of number, string and datetime

11. Supported operators, constants and methods

Supported Operators

Supported conditional statements

Supported logical and math functions

Supported Constants

Supported text functions

Supported date&time functions