JS equivalents to some GWBasic?

[Lynx]

Is there a JavaScript equivalent to the old GWBASIC's: LEFT$; RIGHT$; and MID$?

Example:

Let LT$ = LEFT$("Tornado",3) // equals "Tor"
Let RT$ = RIGHT$("Tornado",3) // equals "ado"
Let MD$ = MID$("Tornado",3,3) // equals "rna"


"Tornado", in those examples, is also replaceable with a variable.


Let TT$ = "Tornado"
Let LT$ = LEFT$(TT$,3) // = "Tor"
etc.


Thanks!

[Chris]

The javascript String primitive has several methods to get this done:

1. Let LT$ = LEFT$("Tornado",3) // equals "Tor"
   

   let tt = "Tornado";
   tt.substring(0,3) === "Tor" 
   tt.substr(0,3) === "Tor" 
   tt.slice(0,3) === "Tor" 
   
   

2. Let RT$ = RIGHT$("Tornado",3) // equals "ado"
   

   tt.substring(tt.length-3) == "ado";
   tt.substr(-3) === "ado";
   tt.slice(-3) === "ado"
   
   

3. Let MD$ = MID$("Tornado",3,3) // equals "rna"
   

   tt.substring(2,5) === "rna"
   tt.substr(2,3) === "rna"
   tt.slice(2,5) === "rna"
   

[Lynx]

Thank you very much, Chris!

I went to the link you posted (thank you very much again for that) and if I'm understanding correctly for the MID$ JS equivalents, substring and slice use the ending index (which yields the characters up to, but not including, the end index) as the 2nd parameter - whereas the substr uses the count (how many) from the starting index (including the starting index). Is that correct?

So, if I wanted to get, for example (using let tt = "Tornado"), the "ornad" could be gotten by 1 of these:

tt.substring(1,6)
tt.substr(1,5)
tt.slice(1,6)

Do I have that correct?

Thanks!

[Chris]

If you are using a browser with a built-in debugger then all you need to do is type it into the immediate window/console to see the result

"Tornado".substring(1,6)

Should immediately give you the result and remove any doubt, try any and all iterations

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EDIT: It's been years since I've touched VB but I do recall you could use those methods to assign new characters (e.g. MID$("Tornado",3,3)="yyy" resulting in "Toyyydo") but not possible in JS, you would need to concatenate or splice.