What-If Analysis

What‑If Analysis is a modeling technique used to evaluate how changes in one or more input values affect the result of a formula.

Instead of manually modifying cells and recalculating repeatedly, What‑If Analysis allows you to systematically explore different scenarios and observe how results respond to varying assumptions.

SpreadJS provides three complementary approaches to perform What‑If Analysis:

Data Table Analysis using the SJS.TABLE worksheet function
Goal Seek Analysis using the GC.Spread.Sheets.CalcEngine.goalSeek method
Scenario Analysis using workbook-level scenarios managed by ScenarioManager

Although these features support scenario‑based evaluation, they serve different purposes and operate differently.

Data Table Analysis (SJS.TABLE)

SJS.TABLE evaluates a result cell or range across multiple input combinations and returns the collected results as a dynamic array.

It is implemented as a standard worksheet formula, which means it:

Participates in normal worksheet recalculation
Can be edited, copied, and nested inside other functions
Automatically spills results into adjacent cells

In addition, SJS.TABLE:

Supports dynamic arrays and inline arrays
Allows multiple input variables in a single formula
Supports cross‑sheet references and named ranges

Data Table Analysis is best suited for comparing outcomes across predefined sets of input values.

Goal Seek Analysis

goalSeek is an imperative calculation method that adjusts the value of a specified cell until a formula reaches a desired target result.

Unlike SJS.TABLE, Goal Seek:

Modifies the changing cell directly
Uses an internal numerical solving algorithm
Returns a boolean or Promise<boolean>
Operates through the CalcEngine API rather than a worksheet formula

Goal Seek is best suited for solving inverse problems, such as determining what interest rate produces a specific payment amount.

Scenario Analysis

Scenario Analysis saves named sets of input values and applies them to a workbook to compare different business outcomes.

A scenario stores values for one or more changing cells. When a scenario is applied, SpreadJS writes the stored values to the target cells and recalculates dependent formulas. When the scenario is restored, the affected cells are returned to their captured base values.

Scenario Analysis is best suited for comparing named assumptions, such as optimistic, pessimistic, and break-even forecasts.

Comparison

Feature	Data Table (`SJS.TABLE`)	Goal Seek (`goalSeek`)	Scenario
Type	Worksheet formula	CalcEngine API method	Workbook-level scenario state
Execution model	Declarative	Imperative	Saved and applied value sets
Primary purpose	Evaluate multiple input combinations	Find an input value for a target result	Compare named sets of input assumptions
Returns	Dynamic array	`boolean` or `Promise<boolean>`	Applies or restores worksheet values
Modifies worksheet cells	No	Yes	Yes, when a scenario is applied or restored

Topic	Description
Data Table: SJS.TABLE Function	Syntax, parameters, and common usage patterns
Data Table: Input and Result Rules	Detailed rules for output size and input matching behavior
Data Table: Performance and Calculation	Controlling recalculation and monitoring progress
Goal Seek	API reference and solving behavior
Scenario	Saving, applying, restoring, and managing named scenarios
Excel Compatibility	Import and export behavior for What-If Analysis features

Using What‑If Analysis in SpreadJS Designer

In SpreadJS Designer, What‑If Analysis tools are available on the What‑If Analysis menu.

Options include:

Scenario Manager
Goal Seek
Data Table

SpreadJS Designer displays the What-If Analysis menu with Scenario Manager, Goal Seek, and Data Table commands for evaluating worksheet assumptions.

For details about the Designer interface and configuration workflow, see What-If Analysis.