• Poob@lemmy.ca
    3·
    3 years ago

    i is for index. j is simply the next letter and we’re too lazy to think up something meaningful

  • Sam@sh.itjust.works
    3·
    3 years ago

    When I’m doing coding interviews I always like to start off and say I’m a big fan of very long variable names. “As descriptive as you can be” I say. Then I get to my first for loop. Instead of i I use “iterator” and then when I start a nested loop I use “jiterator” and it always gets a laugh.

  • barsoap@lemm.ee
    1·
    3 years ago

    It depends. x and y are either elements or coordinates, a and b usually elements though in e.g. Haskell reserved (by convention) for type variables.

    The i j k l series is reserved for indices. n m etc. are the counts of something, as such you’ll see i counting up to n. Both are due to mathematical sum notation and general mathematical convention. Random google result:

    Let x1, x2, x3, …xn denote a set of n numbers. x1 is the first number in the set. xi represents the ith number in the set.

    …if you’re using a language in which you use i often chances are you should stop coding in C and get yourself a language with iterators. Manual loops are a bug magnet.

    • catfish@lemmy.ml
      0·
      3 years ago

      And people who iterate over 3D space using firstDimensionIndex, secondDimensionIndex, and thirdDimensionIndex instead of x, y, z have no sense 😜

  • StudioLE@programming.dev
    0·
    3 years ago

    A useful tip I picked up was to use ii instead of j for an inner loop. It’s far more distinct than j.

    If for some terrible reason you have even more inner loops you can easily continue the trend i, ii, iii, iiii, iiiii - or iv, v if you’re feeling roman

    • barsoap@lemm.ee
      1·
      2 years ago

      When you have multiple indices you’re also bound to have multiple cardinals those indices count up to, say foo.length and bar.length, so foo_i and bar_i are perfectly legible and self-documenting. A bit Hungarian but Hungarian is good in small amounts. Unless you’re dealing with width and height in which case it’s x and y but it’s not that width_i would be incomprehensible.