javascript test for nan code example

Example 1: how to check when a number varibal = nan in ts

if (isNaN(number)) {
      number = 0;
}

Example 2: isnan in javascript

var s = userInput[0];
  if(isNaN(s) !== true)
  {
      console.log("yes");
  }
  else
  {
      console.log("no");
  }

Example 3: javascript check if is nan

function isNaN(x) {
   return x !== x;
};
isNaN(NaN);//true