How to find the sum of an array of numbers

Question

Given an array [1, 2, 3, 4], how can I find the sum of its elements? (In this case, the sum would be 10.)

I thought $.each might be useful,

Answer 1

Accuracy

Sort array and start sum form smallest numbers (snippet shows difference with nonsort)

[...arr].sort((a,b)=>a-b).reduce((a,c)=>a+c,0)

arr=[.6,9,.1,.1,.1,.1]

sum     =                       arr.reduce((a,c)=>a+c,0)
sortSum = [...arr].sort((a,b)=>a-b).reduce((a,c)=>a+c,0)

console.log('sum:     ',sum);
console.log('sortSum:',sortSum);
console.log('sum==sortSum :', sum==sortSum);

// we use .sort((a,b)=>a-b) instead .sort() because
// that second one treat elements like strings (so in wrong way)
// e.g [1,10,9,20,93].sort() -->  [1, 10, 20, 9, 93]

For multidimensional array of numbers use arr.flat(Infinity)

arr= [ [ [1,2,3,4],[1,2,3,4],[1,2,3,4] ],
       [ [1,2,3,4],[1,2,3,4],[1,2,3,4] ] ];
      
sum = arr.flat(Infinity).reduce((a,c)=> a+c,0);

console.log(sum);  // 60