How does Javascript's sort() work?

Question

How does the following code sort this array to be in numerical order?

var array=[25, 8, 7, 41]

array.sort(function(a,b){
  return a - b
})

Answer 1

var array=[25, 8, 7, 41]

array.sort(function(a,b){
  console.log(`a = ${a} , b = ${b}`);
  return a - b
});

OUTPUT

• a = 8 , b = 25
• a = 7 , b = 8
• a = 41 , b = 7
• a = 41 , b = 8
• a = 41 , b = 25

in my Browser (Google Chrome Version 70.0.3538.77 (Official Build) (64-bit) ) in the first iteration, the argument a is the Second element in an array and argument b is the First element of an array.

if the Compare function returns

1. Negative Value than b is moved forward to a.
2. positive Value than a is moved forward to b.
3. 0(Zero) both a & b will remain as it is.