Passing a math operator as a parameter

Question

I\'d like to write a function in Javascript that allows me to pass in a mathematical operator and a list of ints and for each item in that list, apply the operator to it.

Answer 1

If all the operations you are planning to do are binary operations, then you can do this

var operations = {
    "+" : function (operand1, operand2) {
        return operand1 + operand2;
    },
    "-" : function (operand1, operand2) {
        return operand1 - operand2;
    },
    "*" : function (operand1, operand2) {
        return operand1 * operand2;
    }
};

function accumulate(list, operator) {
    return list.reduce(operations[operator]);
}

console.log(accumulate([1, 2, 3, 4], "+"));     // 10
console.log(accumulate([1, 2, 3, 4], "-"));     // -8
console.log(accumulate([1, 2, 3, 4], "*"));     // 24