Functions in Coding §

Functions should be small, do one thing §

All things in the function should be at the same abstraction level. You can describe a function with only one level of abstraction by using “TO” paragraphs. This allows readability like a story, “To do a, you must do b”

TO RenderPageWithSetupsAndTeardowns, we check to see whether the page is a test page and if so, we include the setups and teardowns. In either case we render the page in HTML. ¹

“if you can extract another function from it with a name that is not merely a restatement of its implementation” ¹

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Nested structures like if, else, while, for, try, etc should ideally call another function in their code block. This makes the code easier to read and understand. ²

Example

//Write a function that takes in an object, and a method name, using a 2D array "inputObjArray", run each item with the specified method
function 2DLoop(inputObjArray, inputMethod) {
  for(let i=0; i<inputObjArray.length; i++) {
  	for(let i=0; i<inputObjArray.length; i++) {
  		inputObjectArray[i][j].inputMethod();
  	}
  }
}
 
//Calling Example
2DLoop(cellsArray, draw);

References §

Footnotes §

1. FUNCTIONS SHOULD DO ONE THING. THEY SHOULD DO IT WELL. THEY SHOULD DO IT ONLY, CLEAN CODE: A HANDBOOK OF AGILE SOFTWARE CRAFTSMANSHIP Robert C. Martin ↩ ↩²

2. How to Design Good Functions and Classes | Writing Clean Code §

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