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iOS Swift Basics (retired) Collections Modifying an Array

What is the difference between using += and .append for arrays?

Is one of the two functions exclusive to modifying arrays or do they both just have the same purpose? Can someone elaborate on the use of these functions? Thanks!

1 Answer

William Li
William Li
Courses Plus Student 26,868 Points

Hi, Tom Warner , generally speaking

  • use .append when you want to add one item to the end of a list
  • use += when you want to merge all the items from one list into another.
var letters = ["a", "b", "c"]
letters.append("d")           // => ["a","b","c","d"]
letters += ["e", "f", "g"]    // => ["a","b","c","d", "e", "f", "g"]