Variables and expressions

$result = "Hello, World!";
$result2 = "String2";
$result3 = "String 3";
$result4 = "String 4444444444";
    

[$result, $result2, $result3, $result4] = ["Hello, World!", "String2", "String 3", "String 4444444444"];
    

 ($Upgrade_This_Month && (($Current_Year < $File_Year) ||
                                   ($Current_Year == $File_Year && 
                                    $Current_Month < $File_Month))) 

$result.hasOwnProperty("quantity") ? $result.quantity : 0;

var $someObj = {
  dogs: 3,
  cats: 5,
  whales: 1
};
var keys_only = Object.keys($someObj);
 // keys_only evaluates to ==> ["dogs", "cats", "whales"]
    

Summing and averaging values in arrays

To loop through elements of an array and return the total or average value of all elements, you can use two methods: .forEach() and .reduce().

The syntax of the .forEach() method is:

array.forEach(function(currentValue, index, arr), thisValue)

For more information about how the .forEach() method works, see Array.prototype.forEach().

The syntax of the .reduce() method is:

array.reduce(function(total, currentValue, currentIndex, arr), initialValue)

For more information about how the .reduce() method works, see Array.prototype.reduce().

Summing all elements in an array

This example shows how you can sum array elements by using the .forEach() method:

var nums = [2, 4, 6, 8];

var sum; // value to calculate 
var sum = 0; // initial value 
nums.forEach(eachNumber => {
  sum = sum + eachNumber;
});
print(sum); // Returns ==> 2+4+6+8 = 20.
    

This example shows how you can sum array elements by using the .reduce() method:

var nums = [2, 4, 6, 8];
var sum = nums.reduce((a, b) => a + b, 0);
print(sum) // Returns ==> 2+4+6+8 = 20.
    

Calculating the average of all elements in an array

This example shows how you can calculate the average of all the elements in an array by using the .forEach() method:

var nums = [2, 4, 6, 8];
var avg; // what we want to calculate 
avg = 0; // initial value
nums.forEach(eachNumber => {
  avg = avg + eachNumber;
});
// Divide by number of things 
var avg = avg / nums.length; 
print(avg) // Returns ==> 20/4 = 5.
    

This example shows how you can calculate the average of all the elements in an array by using the .reduce() method:

var nums = [2, 4, 6, 8];
var avg = nums.reduce((a, b) => a + b, 0) / nums.length;
print(avg); // Returns ==> (2+4+6+8)/4 = 5.
    

This example shows how to use the .reduce() method with objects properties instead of primitive values like numbers, strings, and booleans.

Schema definition:

{
    "type": "array",
    "items": {
        "type": "object",
        "properties": {
            "name": {
                 "type": "string"
             },
             "age": {
                 "type": "number"
             }
         },
         "required": ["name", "age"]
    }
}
 

Defined array:

$people = [
{ name: "John", age: 35 },
{ name: "Peter", age: 44 },
{ name: "Little Robbie", age: 64 },
{ name: "Alfredo", age: 12 }
];

Calculate average age in the group:

var averageAge = $people.reduce((a, b) => a.age + b.age, 0) / $people.length;
print(averageAge); // Returns: 38.75

Reduce the average to the nearest lesser whole number by using Math.floor() to return an integer result instead of a float number:

var averageAge = Math.floor($people.reduce((a, b) => a.age + b.age, 0) / $people.length);
print(averageAge); // Returns: 38

For more information about how the Math.floor() method works, see Math.floor().

Concatenating strings and variables

To concatenate strings and variables in expressions, use either the JavaScript + operator or template literals.

Using the JavaScript + operator

Use the JavaScript + operator to concatenate strings and variables and construct simple, single-line expressions, such as this example:

'Hello' + ' ' + 'World' // Returns: "Hello World"

Using template literals

Use template literals for multi-line or more complex pieces of text where you want to insert variable values. In a template literal expression, wrap the string in back ticks (``), and then inside the string you can use variables in a ${<variable_name>} format, as shown in this example:

const name = "User1";const greeting = `Hello, ${name}! Welcome to IBM Concert Workflows®.`;console.log(greeting); 

Manipulating strings

Use string methods such as .split() and .join() to extract or format text from paths or structured data.

Splitting delimited strings into arrays

Use the .split() method to convert a string into an array based on a specified delimiter, such as "/", as shown in this example:

var $path = "animal/cat/tom";
var $splitPath = $path.split("/");

print($splitPath); // Returns: ["animal", "cat", "tom"]
print($splitPath[$splitPath.length - 1]); // Returns: "tom"
      

For more information about how the .split() method works, see String.prototype.split().

Converting array elements into strings

Use the .join() method to convert an array into a single string with a custom separator, as shown in this example:

var $stuff = ["animal", "cat", "tom"];
print($stuff.join(" AND")); // Returns: "animal AND cat AND tom"
      

For more information about how the .join() method works, see Array.prototype.join().