javascript - How is this minified JS the same as this uncompressed version? -

Then it looks like my uncompressed:

  function extract dropdown value () { Var all_selected = true; $ ('.Variant_options select'). Each (function () {if (this.selectedIndex == 0) {all_selected = false;}});   
 This compressed version is:  
  extractDropdownValues ​​() {var e =! 0; Select $ (".Variant_options"). Each (function) {this.selectedIndex == 0 & amp; & Amp; (D = 1)!});   
 I  E =! 0  is confused with the compressed version of  all_selected = true  and  it.Blied Index == 0  if the statement is in the compressed version, this  If  is indicating this index == 0, then set it to false.  
 But in the compressed version, it seems that this is the value of  selected index  for 0 and  & amp; Amp; Amp; Amp; Amp; Amp;  all_selected = false  (i.e.  e =! 1 ) for . But I do not want the result as  if  condition, which should be the result after  if  condition is satisfied.  
 Am I reading this wrong?  
 PS compressed version is not working in production, but is working in uncompressed dev. I am not sure that both are correlated, but on the surface, they do not consider me equal.  
  Edit 1   
 As I suspect, I read the JS Run mini-js through prefifiers, and the result is:  
  function extractdowndown value () {var e =! 0; $ (".variant_options select"). Each (function () {this.selectedIndex == 0 & amp; (e =! 1)});   
 Soo ... Ah ... WTF is getting here?   
 
 
 0 is false in Boolean form, so the boolean prohibition of 0 (false) is true.  
 Similarly, 1 boolean form is correct, so the boolean reject of 1 is wrong.  
  & amp; Amp; Amp; & Amp; Amp; Amp;;  is short circuiting and operator, which means that as soon as it knows that its results get a quick return - if its first operand is wrong, then it returns false if its first operation is correct, after that He evaluates the second operand and gives returns.  
 Then  E =! 1  Only if  this.selectedIndex == 0  is true (because if it is wrong, then it knows that it is returning incorrectly and is closing soon).