Black Box Testing Techniques

Learn black box testing techniques that focus on functionality without knowing internal code

45 min•By Priygop Team•Last updated: Feb 2026

Black Box Testing Principles

Tests functionality without knowing internal structure
Focuses on inputs and outputs
Tests from user perspective
Validates requirements and specifications
Independent of implementation details

Black Box Testing Techniques

Example

// Equivalence Partitioning
// Divide input data into valid and invalid groups
function testAgeValidation() {
    // Valid partitions: 18-65
    // Invalid partitions: <18, >65, non-numeric
    
    // Valid test cases
    testValidAge(25); // Should pass
    testValidAge(18); // Should pass
    testValidAge(65); // Should pass
    
    // Invalid test cases
    testInvalidAge(17); // Should fail
    testInvalidAge(66); // Should fail
    testInvalidAge("abc"); // Should fail
}

// Boundary Value Analysis
// Test values at boundaries of input ranges
function testBoundaryValues() {
    // For age range 18-65
    // Test boundaries: 17, 18, 19, 64, 65, 66
    
    testBoundary(17); // Just below minimum
    testBoundary(18); // Minimum valid
    testBoundary(19); // Just above minimum
    testBoundary(64); // Just below maximum
    testBoundary(65); // Maximum valid
    testBoundary(66); // Just above maximum
}

// Decision Table Testing
// Test different combinations of conditions
function testLoginDecisionTable() {
    // Conditions: Valid username, Valid password, Account active
    // Rules: All combinations of true/false
    
    // Rule 1: All true -> Login successful
    testLogin(true, true, true); // Should pass
    
    // Rule 2: Invalid username -> Login failed
    testLogin(false, true, true); // Should fail
    
    // Rule 3: Invalid password -> Login failed
    testLogin(true, false, true); // Should fail
    
    // Rule 4: Account inactive -> Login failed
    testLogin(true, true, false); // Should fail
}