Calculator-1/script.js at main · Git-SOJO/Calculator-1 · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
const calculator = document.querySelector('.calculator');
const keys = calculator.querySelector('.keys');
const display = document.getElementById('display');

keys.addEventListener('click', e => {
    if (!e.target.matches('button')) return;

    const key = e.target;
    const action = key.dataset.action;
    const keyContent = key.textContent;
    const displayedNum = display.textContent;

    if (!action) {
        if (displayedNum === '0' || calculator.dataset.previousKeyType === 'operator') {
            display.textContent = keyContent;
        } else {
            display.textContent = displayedNum + keyContent;
        }
        calculator.dataset.previousKeyType = 'number';
    }

    if (
        action === 'add' ||
        action === 'subtract' ||
        action === 'multiply' ||
        action === 'divide'
    ) {
        calculator.dataset.firstValue = displayedNum;
        calculator.dataset.operator = action;
        calculator.dataset.previousKeyType = 'operator';
    }

    if (action === 'decimal') {
        if (!displayedNum.includes('.')) {
            display.textContent = displayedNum + '.';
        }
        calculator.dataset.previousKeyType = 'decimal';
    }

    if (action === 'clear') {
        display.textContent = '0';
        calculator.dataset.firstValue = '';
        calculator.dataset.operator = '';
        calculator.dataset.previousKeyType = 'clear';
    }

    if (action === 'calculate') {
        const firstValue = calculator.dataset.firstValue;
        const operator = calculator.dataset.operator;
        const secondValue = displayedNum;
        display.textContent = calculate(firstValue, operator, secondValue);
        calculator.dataset.previousKeyType = 'calculate';
    }
});

function calculate(n1, operator, n2) {
    let result = '';

    if (operator === 'add') {
        result = parseFloat(n1) + parseFloat(n2);
    } else if (operator === 'subtract') {
        result = parseFloat(n1) - parseFloat(n2);
    } else if (operator === 'multiply') {
        result = parseFloat(n1) * parseFloat(n2);
    } else if (operator === 'divide') {
        result = parseFloat(n1) / parseFloat(n2);
    }

    return result;
}