Can anyone explain me how the output came??

Question

// JAVASCRIPT ARRAY METHOD - slice()

var arr=["AngularJS","Node.js","JQuery","Bootstrap"]  
var result=arr.slice(-4,-1); 

Output: AngularJS , Node.js , JQuery

Answer 1

Numbers in parentheses are negative index

INDEX 0 (-4) 1 (-3) 2 (-2) 3 (-1)
VALUE AngularJS NodeJS jQuery Bootstrap

arr.slice( -4, -1 ) means slice array <arr> from index -4 (or index 0) up to index -1 (or index 3 exclusively ).