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JavaScript JavaScript and the DOM (Retiring) Making Changes to the DOM Styling Elements

Devjyoti Ghosh
Devjyoti Ghosh
2,422 Points
Posted by Devjyoti Ghosh
Devjyoti Ghosh
2,422 Points

For the first time toggling requires 2 clicks to hide with my code

Here is my code http://w.trhou.se/r2dgh13tiv

The only change I have made from the teachers code is that I have reversed the if else statements. I am not sure why that leads to using 2 clicks to hide the content for the first time.

1 Answer

Steven Parker
Steven Parker
231,271 Points
Steven Parker
Steven Parker
231,271 Points

The display mode is not (explicitly) "block" initially.

By testing for "none", the example code in the video works no matter what value display has to begin with. This makes the code more robust and less likely to to affected by browswer differences.

Without moving any lines, you can make your code work by changing both instances of "block" to empty strings:

toggleList.addEventListener("click", () => {
  if (list.style.display === "") {
    toggleList.textContent = "Show List";
    list.style.display = "none";
  } else {
    toggleList.textContent = "Hide List";
    list.style.display = "";
  }
});
Devjyoti Ghosh
Devjyoti Ghosh
2,422 Points
Devjyoti Ghosh
Devjyoti Ghosh
2,422 Points

What's the difference between block and empty strings?

Steven Parker
Steven Parker
231,271 Points
Steven Parker
Steven Parker
231,271 Points

If there is no CSS they will be the same. But setting "block" has inline specificity (the highest), which will override any CSS rules. The empty string just removes any inline setting, whilch will allow any existing CSS setting to apply.