javascript - I want to have a dropdown menu where you choose the number instead of the variable -

the "var aantal = 10" gives me 10 traingles user insert own amount of triangles.

      var aantal = 10;          var triangle = [];        (var = 0; < aantal; i++){           triangle[i] = new triangle;           triangle[i].xleft = 20 + 30*i;           triangle[i].yleft = 20 + 20*i;        } 

a quick , easy way ask user input in browser via window.prompt method.

this stops code until user presses "ok" or "cancel" in popup window. when user fills in value , presses "ok", value returned string. here's example:

var userinput = prompt("how many triangles want?", 10);  var count = parseint(userinput, 10);    (var = 0; < count; += 1) {    console.log("triangle " + i);  }

note need explicitly convert string number. additionally, might want check null or nan: when user presses "cancel" or fills in invalid data, you'll need have fallback.

once works, might want try create <input type="number"> html element , data there.