different programming languages/words in text editors

[snippsat]

Thank You,as I said and from what you gave as demo ,to do the same function like Hello World , in Python , C++ or JavaScript, the three all use different code to produce the same outcome,correct ?
If I am correct ,why was this done this way ?

Yes the produce the same output,but the usage languages can different task as eg JavaScript run mostly in Browser.

A person that learns say Python and knows nothing else would not be able to program with say JavaScript until he or she learned JavaScript ,correct ?

If know Python then JavaScript is similar is not that big a difference.
If i just copy some JavaScript code from web.

function returnSum(first, second)
        {
          var sum = first + second;
          return sum;
        }
      var firstNo = 78;
      var secondNo = 22;
      console.log(firstNo + " + " + secondNo + " = " + returnSum(firstNo,secondNo));

Output:
78 + 22 = 100

Can easily write this in Python.

def return_sum(first, second):
    mysum = first + second
    return mysum

firstNo = 78
secondNo = 22
print(f'{firstNo} + {secondNo} = {return_sum(firstNo, secondNo)}')

Output:
78 + 22 = 100

So the output is the same.
JavaScript is popular for web-development as together with HTML/CSS it can use Brower for output.
So different langue can have different usage even it outcome is the same.