How to sum arrays in JavaScript? Introduction to common methods

This article will share with you some common methods for summing JavaScript arrays. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to everyone.

Common methods for summing JS arrays

1. for loop

var arr = [1,2,3]; function sum(arr) { var s = 0; for (var i = 0;i
      
2. forEach traversal
      
var arr = [1,2,3]; function sum(arr) { var s = 0; arr.forEach(function(val, idx, arr) { s += val; }, 0); return s; }; console.log(sum(arr));//6
      
3. reduce
      
var arr = [1,2,3]; function sum(arr) { return arr.reduce(function(acr, cur){ return acr + cur; }); } console.log(sum(arr));//6
      
4. Recursion
      
var arr = [1,2,3]; function sum(arr) { if(arr.length == 0){ return 0; } else if (arr.length == 1){ return arr[0]; } else { return arr[0] + sum(arr.slice(1)); } } console.log(sum(arr));//6
      
5. eval
      
var arr = [1,2,3]; function sum(arr) { return eval(arr.join("+")); }; console.log(sum(arr));//6
      
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