Programming Without Ifs

Kyle Coberly -- Node.js Meetup, January 17, 2019

Learning Objectives

1. Define cyclomatic complexity
2. Recall 3 ways to avoid ifs
3. Discuss 3 ways to make an if statement better

Cyclomatic Complexity

• The number of independent paths that are possible in code
• Loops do not add cyclomatic complexity
• Conditionals add a cc because they provide at least two possible paths
• if, else, else if
• case
• catch
• &&
• a ternary

Complex Code is Problematic because...

• You have to write more test cases (probably reduces test coverage)
• More possible points of failure
• Harder to extend
• Harder to read

Recall 3 ways to avoid ifs

1. Functional chains

• best used for data transformations

2. Dictionary Lookup

• a good replacement for switch statements

3. Dynamic Dispatch

• variable behavior
• to replace a switch statement that accepts different data types (?)

3 ways to make an if statement better

1. Combine conditionals AKA flatten nested ifs
2. Wrap blocks in functions
3. Return a ternary