1// Create a function (you decide the name) that logs out the number 42 
2// to the console
3
4// Call/invoke the function
5
6 function number(){
7     console.log(42)
8 }
9 
10 number()
11//result = 42

1function runFunction() {
2  myFunction();
3}
4
5function myFunction() {
6  alert("runFunction made me run");
7}
8
9runFunction();

1function myFunc(p1, p2, pN)
2{
3     // here "this" equals "myThis"
4}
5let myThis = {};
6
7// call myFunc using myThis as context.
8// pass params to function arguments.
9myFunc.call(myThis, "param1", "param2", "paramN");

1function abc() {
2  alert('test');
3}
4
5var funcName = 'abc';
6
7window[funcName]();

1// calling our function
2displayGreeting();

1/*
2Write a function sum that takes an array of numbers and 
3returns the sum of these numbers. 
4Write a function mean that takes an array of numbers and 
5returns the average of these numbers. 
6The mean function should use the sum function.
7*/
8function sum (arr) {
9    let suma = 0;
10    for (let i = 0; i < arr.length; i++) {
11        
12        let num= parseInt(arr[i]);
13        suma += num;
14    }
15    return suma;
16  }
17  
18  function mean (arr) {
19    let average = sum(arr) /arr.length;
20    
21    return average;
22  }