JavaScript

// The method assumes that the length of the two arrays are the same
function sumArray(initial, operator, data) {
    var fix = initial;
    for (var i = 0; i < operator.length; i++) {
        if (operator[i] === "-") {
            fix = fix - data[i];
        }
        else if (operator[i] === "+") {
            fix = fix + data[i];
        }
        else if (operator[i] === "*") {
            fix = fix * data[i];
        }
        else if (operator[i] === "/") {
            fix = fix / data[i];
        }
    }
    return fix;
}
console.log(sumArray(5, ["-", "+", "*"], [4, 5, 6,]));

// Assumes that the length of the encoder is usually longer
function encoder(raw, encode) {
    var data = [];
    for (var i = 0; i < raw.length; i++) {
        var index = raw.indexOf(raw[i]);
        var code = encode[index];
        data.push(code);
    }
    return data;
}
console.log(encoder(["a", "b", "a", "c"], ["1", "2", "3", "4"]));