calculator/script.js at main · satya551/calculator · 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
console.log("working check");
let keys=document.querySelector(".keys");
let raughCal=document.querySelector(".display");
let result=document.querySelector(".ans");
raughCal.innerText="";
let cal="";
let preValue="";
let currNum="";
let operators=["+","-","*","/"];
keys.addEventListener("click",(evt)=>{
     let crtClick=evt.target.innerText;
     // don't allow to user click any operator at initial
     if(cal==="" && (crtClick==="+" || crtClick==="*" || crtClick=== "/" || crtClick==="-")){
          raughCal.innerText="";

     }
     //checking changing operator are not same
     else if(crtClick!=="AC" && crtClick!=="Del" && crtClick!=="="){
          if(crtClick==="+" || crtClick==="-" || crtClick==="*" || crtClick==="/"){
                  currNum="";
               }
          if((preValue==="+"  && crtClick==="+") || (preValue==="-" && crtClick==="-") || (preValue==="*"  && crtClick==="*") || (preValue==="/" && crtClick==="/") || (preValue==="(" && crtClick===")")){
               if(preValue==="(" && crtClick===")"){
                    preValue="(";
               }
          }
          // changing the current operator
          else if((preValue==="+"  && (crtClick==="-" || crtClick==="*" || crtClick==="/")) || (preValue==="-" && (crtClick==="+" || crtClick==="*" || crtClick==="/")) ||
          (preValue==="*"  && (crtClick==="-" || crtClick==="+" || crtClick==="/")) ||
          (preValue==="/" && (crtClick==="-" || crtClick==="*" || crtClick==="+"))
          ){
              let cngOprtr=String(raughCal.innerText);
              let changeOptr=cngOprtr.slice(0,-1);
              raughCal.innerText=changeOptr;
              raughCal.innerText=changeOptr+evt.target.innerText;
              cal=raughCal.innerText;
              preValue=crtClick;
              if(crtClick==="+" || crtClick==="-" || crtClick==="*" || crtClick==="/"){
                  currNum="";
               }

          }
          else if(crtClick==="."){
               if(!currNum.includes(".")){
                  if(currNum===""){
                    currNum="0."
                    raughCal.innerText=raughCal.innerText+evt.target.innerText;
                  }
                  else if(currNum!==""){
                    currNum+=".";
                    raughCal.innerText=raughCal.innerText+evt.target.innerText;

                  }
               }
               else{
                    raughCal.innerText=raughCal.innerText;
                    currNum=currNum;
               }
          }
          else{
               raughCal.innerText=raughCal.innerText+evt.target.innerText;
               cal=raughCal.innerText;
               preValue=crtClick;
               currNum=currNum+evt.target.innerText;
          }
     }
     // handling AC button
     else if(crtClick==="AC"){
          cal="";
          raughCal.innerText="";
          currNum="";
          result.innerText="0";
     }
     // "=" button clicked
     if(crtClick==="="  || crtClick==="+" || crtClick==="-" || crtClick==="*" || crtClick==="/"){
          try{
            let str=raughCal.innerText;
            let lastChar=str.charAt(str.length-1);
            if(lastChar==="+" || lastChar==="-" || lastChar==="*" || lastChar==="/"){
               let expression=str.slice(0,-1);
               let answer=eval(expression);
               result.innerText=answer;

            }
            else{

              let answer=eval(raughCal.innerText);
              result.innerText=answer;
            }
          }
          catch(error){
               result.innerText="enter valid expression";
          }

     }
})