PHP code comments small details

Code comments can be said to be more important than the code itself. I would like to warn newcomers that they must develop the habit of writing comments, otherwise they will only harm others and not benefit themselves. Here are some ways to ensure that the comments you write in your code are friendly. To sum up, "5 dos and 3 don'ts"
1. Don't repeat what the reader already knows (×)

If you can see the function just by looking at the method name and the code, there is no need to write comments.

// If the color is red, turn it green
if (color.is_red()) {
  color.turn_green();
}

2. Comment to explain reasoning and history (√)

If the business logic in the code may need to be updated or changed in the future, then comments should be left:

/* The API currently returns an array of items
even though that will change in an upcoming ticket.
Therefore, be sure to change the loop style here so that
we properly iterate over an object */
var api_result = {items: ["one", "two"]},
    items = api_result.items,
    num_items = items.length;
for(var x = 0; x < num_items; x++) {
  ...
}

3. Don’t write very long comments on the same line（×）

Nothing is better than dragging the horizontal scroll bar Reading the comments made the developers even more outraged. In fact, most developers choose to ignore such comments because they are really inconvenient to read.

function Person(name) {
  this.name = name;
  this.first_name = name.split(" ")[0]; // This is just a shot in the dark here. If we can extract the first name, let's do it
}

Fourth, long comments should be placed above the logic and short comments at the back（√）

Comments can be placed next to the code if they do not exceed 120 characters. Otherwise, the comment should be placed directly above the statement.

if (person.age < 21) {
  person.can_drink = false; // 21 drinking age
  /* Fees are given to those under 25, but only in
     some states. */
  person.has_car_rental_fee = function(state) {
    if (state === "MI") {
      return true;
    }
  };
}

5. Don’t add unnecessary comments just for the sake of comments (×)

Superfluous Comments can cause confusion. Maybe in school you were taught to comment out all statements, which would help developers understand better. But this is wrong. If anyone says that, give him a slap in the face right away. It goes without saying that code should be kept clean and concise. If your code requires line-by-line explanation, then the most important thing you need to do is refactor.

if (person.age >= 21) {
  person.can_drink = true; // A person can drink at 21
  person.can_smoke = true; // A person can smoke at 18
  person.can_wed = true; // A person can get married at 18
  person.can_see_all_movies = true; // A person can see all movies at 17
  //I hate babies and children and all things pure because I comment too much
}

6. Comments must be spelled correctly（√）

Do not spell out the code comments Making excuses for mistakes. The IDE can check spelling for you. If you don’t have this function, then download the plug-in and do it yourself!
7. Practice more（√）
Practice makes perfect. Try writing some useful comments and ask other developers if your comments are useful. Over time, you'll learn what constitutes a friendly comment.
8. Review other people’s comments（√）
When reviewing code, we often ignore checking Note. Don't be afraid to ask for more comments, you should ask questions. If everyone developed the good habit of writing good notes, the world would be a better place.
9. Summary of the essence of what you must know about comments

Comments are a very important part of the development process, but we shouldn't comment for the sake of comments. Comments should be useful, concise, and should complement the code. Comments should not be used to explain the code line by line, instead they should be used to explain business logic, reasoning, and implications for the future.