add to every element in array js code example

Example 1: js array add every element of array

var array = ['a', 'b', 'c'],
    result = array.reduce((r, a) => r.concat(a, 0), [0]);
    
console.log(result);

Example 2: javascript add 1 to each element in array

var numberarr2 = numberarr.map( function(value) { 
    return value - 1; 
} );