(see factorial)Normally dots should be used only where the pattern to be followed is clear, the exception being to show the indefinite continuation of an irrational number such as:

  
    
      
        π
        =
        3.14159265
        …
      
    
    {\displaystyle \pi =3.14159265\ldots }
  Sometimes, it is useful to display a formula compactly, for example:

  
    
      
        1
        +
        4
        +
        9
        +
        ⋯
        +
        
          n
          
            2
          
        
        +
        ⋯
        +
        400
      
    
    {\displaystyle 1+4+9+\cdots +n^{2}+\cdots +400}
  Another example is the set of positive zeros of the cosine function:

  
    
      
        
          {
          
            
              
                π
                2
              
            
            ,
            
              
                
                  3
                  π
                
                2
              
            
            ,
            
              
                
                  5
                  π
                
                2
              
            
            ,
            …
          
          }
        
      
    
    {\displaystyle \left\{{\frac {\pi }{2}},{\frac {3\pi }{2}},{\frac {5\pi }{2}},\ldots \right\}}
  There are many related uses of the ellipsis in set notation.
One of its most common uses is in defining ranges or sequences, for instance 1..10 means all the numbers from 1 through 10. This is used in many languages, including Pascal, Modula, Oberon, Ada, Haskell, Perl, Ruby, Rust, Swift, Kotlin, Bash shell and F#. It is also used to indicate variadic functions in the C, C++ and Java languages. See Ellipsis (programming operator). HTML and CSS
The CSS text-overflow property can be set to ellipsis, which cuts off text with an ellipsis when it overflows the content area. On Internet chat rooms and in text messaging
The ellipsis is a non-verbal cue that is often used in computer-mediated interactions, in particular in synchronous genres, such as chat. The reason behind its popularity is the fact that it allows people to indicate in writing several functions:

The sign of ellipsis can function as a floor holding device, and signal that more is to come, for instance when people break up longer turns in chat. Dot-dot-dot can be used systematically to enact linguistic politeness, for instance indicating topic change or hesitation. Suspension dots can be turn construction units to signal silence, for example when indicating disagreement, disapproval or confusion.Although an ellipsis is technically complete with three periods (...), its rise in popularity as a "trailing-off" or "silence" indicator, particularly in mid-20th-century comic strip and comic book prose writing, has led to expanded uses online. Today, extended ellipses anywhere from two to dozens of periods have become common constructions in Internet chat rooms and text messages.