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Multi-step Signup Form (Reactive Forms)

By FrontendAtlas Team · Updated Jan 30, 2026

Build a 3-step signup flow using Angular reactive forms: basic info, address info, and a summary + submit step. Each step should only allow moving forward when its fields are valid.

Use a standalone Angular component as the root component.
Use Angular reactive forms (FormGroup, FormBuilder, Validators) with nested form groups.

What you’ll build / What this tests

This premium angular coding focuses on Multi-step Signup Form (Reactive Forms). You’ll apply forms and reactive-forms thinking with intermediate level constraints. The prompt emphasizes Build a 3-step signup flow using Angular reactive forms: basic info, address info, and a summary….

Learning goals

Translate the prompt into a clear angular API signature and return shape.
Apply forms, reactive-forms, validation techniques to implement multi-step signup form (reactive forms).
Handle intermediate edge cases without sacrificing readability.
Reason about time/space complexity and trade-offs in angular.

Key decisions to discuss

Define the exact input/output contract before coding.
Prioritize predictable edge-case handling over micro-optimizations.

Evaluation rubric

Correctness: covers required behaviors and edge cases.
Clarity: readable structure and predictable control flow.
Complexity: avoids unnecessary work for large inputs.
API discipline: no mutation of inputs; returns expected shape.
Testability: solution is easy to unit test.

Constraints / Requirements

Use a standalone Angular component as the root component.
Use Angular reactive forms (FormGroup, FormBuilder, Validators) with nested form groups.
Step 1 (Basic info): capture name and email fields.
Step 2 (Address info): capture street, city, country, and optionally postalCode.
Step 3 (Summary): display a read-only summary of all collected values and provide a Submit button.
The Next button should be disabled unless the current step's group is valid.
Preserve entered values when navigating back and forth between steps.
(Optional) Add a Back button to move to the previous step.
The flow starts on Step 1 (Basic info).
On Step 1, Next is disabled until both name and email are valid (required + valid email).

Mini snippet (usage only)

// Example usage
const input = /* multi-step signup form (reactive forms) input */;
const result = solve(input);
console.log(result);

// Edge case check
const empty = input ?? null;
const fallback = solve(input);
console.log(fallback);

// Expected: describe output shape, not the implementation
// (no solution code in preview)

Common pitfalls

Mutating inputs instead of returning a new value.
Skipping edge cases like empty input, duplicates, or nulls.
Overlooking time complexity for large inputs.