calc.github.io/script.js at main · seiyanz16/calc.github.io · 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
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
document.body.addEventListener("change", function(e){
    let target = e.target;
    container = document.body.querySelector(".container")

    switch (target.id) {
        case "firstToggle":
            container.setAttribute("data-theme", "one");
            break;
        case "secToggle":
            container.setAttribute("data-theme", "two");
            break;
        case "thirdToggle":
            container.setAttribute("data-theme", "three")
            break;
        default:
            return;
    }
});
const calculator = {
    displayNumber : '399.981',
    operator : null,
    firstNumber : null,
    waitingForSecondNumber : false
};
const inputDigit = (digit) => {
    if(calculator.waitingForSecondNumber === true){
        calculator.displayNumber = digit;
        calculator.waitingForSecondNumber = false;
    } else {
        calculator.displayNumber += digit;
    }
};
const inputDecimal = (dot) => {
    if (calculator.waitingForSecondNumber === true) {
        calculator.displayNumber = '0.'
        calculator.waitingForSecondNumber = false;
        return;
    }

    if (!calculator.displayNumber.includes(dot)) {
      calculator.displayNumber += dot;
    }
};
const handleOperator = (operator) => {
    if (!calculator.waitingForSecondNumber){
        calculator.operator = operator;
        calculator.waitingForSecondNumber = true;
        calculator.firstNumber = calculator.displayNumber
        // calculator.displayNumber = '0'
    } else {
        alert('operator already set!');
    }
};
const performaCalculation = () => {
    let computation
    const prev = parseFloat(calculator.firstNumber)
    const current = parseFloat(calculator.displayNumber)
    if (isNaN(prev) || isNaN(current)) return
    switch (calculator.operator) {
      case '+':
        computation = prev + current
        break
      case '-':
        computation = prev - current
        break
      case 'x':
        computation = prev * current
        break
      case '/':
        computation = prev / current
        break
      default:
        alert("operator doesn't already set!");
    }
    calculator.displayNumber = `${parseFloat(computation.toFixed(7))}`
    calculator.operator = undefined
}
const resetCalculator = () => {
    calculator.displayNumber = '0';
    calculator.operator = null;
    calculator.firstNumber = null;
    calculator.waitingForSecondNumber = false
};
const deleteValue = () => {
    if(calculator.displayNumber === '0'){
        calculator.displayNumber = '0'
    } else {
    calculator.displayNumber = calculator.displayNumber.slice(0,-1);
    };
};
const updateDisplay = () => {
    document.querySelector(".display-number").innerHTML = calculator.displayNumber;
};
updateDisplay();

const buttons = document.querySelectorAll(".button");
for (let button of buttons){
    button.addEventListener('click', function(event){
        const target = event.target;

        if(target.classList.contains('reset')){
            resetCalculator();
            updateDisplay();
            return;
        }
        if(target.classList.contains('delete')){
            deleteValue();
            updateDisplay();
            return;
        }
        if (target.classList.contains('operator')){
            handleOperator(target.innerHTML);
            updateDisplay()
            return;
        }
        if (target.classList.contains('equals')) {
            performaCalculation();
            updateDisplay();
            return;
        }

        inputDigit(target.innerHTML);
        updateDisplay()
    });
}