Php-about embedding loop statements in htm files

Now I want to create a department permission control page. First, I wrote several arrays in the PHP file, including Level 1 department, level 2 department, and Level 3 department. These three departments are affiliated. For example, the first-level department is a one-dimensional array, the second-level department is a two-dimensional array, and the third-level department is a three-dimensional array. In the htm file, I want to use loop display. Add a checkbox to each department at level 3, select and submit, and then process it in the PHP file. The problem is that it is unclear how to write a loop. I found the following statement: checked & quot; true & quot; & lt ;! -- {If}-phploophtm loop

Now I want to create a department permission control page. First, I wrote several arrays in the PHP file, including Level 1 department, level 2 department, and Level 3 department. These three departments are affiliated. For example, the first-level department is a one-dimensional array, the second-level department is a two-dimensional array, and the third-level department is a three-dimensional array. In the htm file, I want to use loop display. Add a checkbox to each department at level 3, select and submit, and then process it in the PHP file. The problem is that it is unclear how to write a loop. I found the following statement:

                                                                                    checked="true"                              
                                    >                               $regular[name]                                                   
   

I only need the $ regular [name] and change it to my own name. How should I write the department array? Is there a loop in the htm language? Or is it embedded in other languages?
In this regard, what should I look?