Update evaluate-expressions-in-workflows-and-actions.md

Explained how operators are used. 

issue-#37006

Author: silky-x0

content/actions/writing-workflows/choosing-what-your-workflow-does/evaluate-expressions-in-workflows-and-actions.md

@@ -109,21 +109,51 @@ env:
 * {% data variables.product.prodname_dotcom %} ignores case when comparing strings.
 * Objects and arrays are only considered equal when they are the same instance.
 
-{% data variables.product.prodname_dotcom %} offers ternary operator like behaviour that you can use in expressions. By using a ternary operator in this way, you can dynamically set the value of an environment variable based on a condition, without having to write separate if-else blocks for each possible option.
-
-### Example
+% data variables.product.prodname_dotcom %} provides a way to create conditional logic in expressions using binary logical operators (`&&` and `||`). This pattern can be used to achieve similar functionality to the ternary operator (`?:`) found in many programming languages, while actually using only binary operators.
 
+## Example:
 {% raw %}
-
 ```yaml
 env:
   MY_ENV_VAR: ${{ github.ref == 'refs/heads/main' && 'value_for_main_branch' || 'value_for_other_branches' }}
 ```
-
 {% endraw %}
 
-In this example, we're using a ternary operator to set the value of the `MY_ENV_VAR` environment variable based on whether the {% data variables.product.prodname_dotcom %} reference is set to `refs/heads/main` or not. If it is, the variable is set to `value_for_main_branch`. Otherwise, it is set to `value_for_other_branches`.
-It is important to note that the first value after the `&&` must be truthy. Otherwise, the value after the `||` will always be returned.
+In this example, we're using logical operators to set the value of the `MY_ENV_VAR` environment variable based on whether the {% data variables.product.prodname_dotcom %} reference is set to `refs/heads/main` or not.
+
+### How It Works
+
+This expression uses two binary operators:
+- `&&` (logical AND): Returns the right operand if the left operand is truthy, otherwise returns the left operand
+- `||` (logical OR): Returns the left operand if it's truthy, otherwise returns the right operand
+
+### Order of Operations
+
+The order of operations is important to understand:
+1. The equality comparison (`==`) is evaluated first
+2. The logical AND (`&&`) has higher precedence than logical OR (`||`)
+3. The expression is evaluated as `(github.ref == 'refs/heads/main' && 'value_for_main_branch') || 'value_for_other_branches'`
+
+### Step-by-Step Evaluation
+
+When `github.ref == 'refs/heads/main'` is true:
+1. `github.ref == 'refs/heads/main'` evaluates to `true`
+2. `true && 'value_for_main_branch'` evaluates to `'value_for_main_branch'`
+3. `'value_for_main_branch' || 'value_for_other_branches'` evaluates to `'value_for_main_branch'`
+
+When `github.ref == 'refs/heads/main'` is false:
+1. `github.ref == 'refs/heads/main'` evaluates to `false`
+2. `false && 'value_for_main_branch'` evaluates to `false`
+3. `false || 'value_for_other_branches'` evaluates to `'value_for_other_branches'`
+
+### Important Considerations
+
+- This is NOT a true ternary operator (which would take the form `condition ? true_value : false_value`), but rather two binary operators arranged to achieve similar functionality
+- The expression after `&&` must evaluate to a truthy value to work correctly
+- If the expression after `&&` is falsy (empty string, zero, false, null), the value after `||` will be returned even if the initial condition is true
+- The evaluation follows standard JavaScript-like operator precedence rules
+
+For complex conditional logic, you might prefer using job conditionals or separate if-steps.
 
 ## Functions