Question

所以我在写一个计算器，在等号下苦苦挣扎，我试图做一些简单的床褥活动（没有花花公子，没有指数），但是我的代码一直返回0，就像if statement aregeting完全跳过

我不知道是什么原因造成的，因为我没有收到错误

function equal(){
        let exp = document.form.textview.value;
        let expArray = exp.split(/\b/);
        console.log(expArray);   //<-if something doesn't work check this
        let total = 0;
        var lastOperator = "+";
        var lastDig = 0;
        for(let i = 0 ; i < expArray.length; i++){
          var dig = expArray[i].trim(); //value of "i", the item currently in the loop
          if(isNaN(dig) == true){
             console.log("string")
           }
          else if(isNaN(dig) == false){
            console.log('not string');
              if (dig == "/"){ //this whole section gets skipped :(
                var a = i + 1;
                var p = i - 1;
                var aDig = parseFloat(expArray[a].trim); //value after "i"
                var bDig = parseFloat(expArray[p].trim); // value before  "i"
                var sDig = aDig / bDig;
                total = expArray.splice(bDig, 3, sDig);
              }

              else if ( dig == "*"){
                var a = i + 1;
                var p = i - 1;
                var aDig = parseFloat(expArray[a].trim); //value after "i"
                var bDig = parseFloat(expArray[p].trim) // value before  "i"
                var sDig = aDig * bDig;
                total = expArray.splice(bDig, 3, sDig);
              }
              else if ( dig == "+"){
                var a = i + 1;
                var p = i - 1;
                var aDig = parseFloat(expArray[a].trim); //value after "i"
                var bDig = parseFloat(expArray[p].trim)// value before  "i"
                var sDig = aDig + bDig;
                total = expArray.splice(bDig, 3, sDig);
                console.log(expArray.splice(bDig, 3, sDig));
              }
              else if( dig == "-"){
                var a = i + 1;
                var p = i - 1;
                var aDig = parseFloat(expArray[a].trim); //value after "i"
                var bDig = parseFloat(expArray[p].trim) // value before  "i"
                var sDig = aDig - bDig;
                total = expArray.splice(bDig, 3, sDig);
            }
          }

            }
            document.form.textview.value = total;

        } ```

Answer 1

我不确定您要在这里做什么。 isNan（numberContent）将返回false＆isNan（stringContent）将返回true。您使用错误。第一个if应该为isNaN(dig) == false和第二个isNaN(dig) == true。


        let exp = "1/1*3";
        let expArray = exp.split(/\b/);
        console.log(expArray);   //if something doesn't work check this
        var previousValue= parseFloat(expArray[0].trim().toString());
        for(let i = 1 ; i < expArray.length; i++){
        var dig = expArray[i].trim(); //value of "i", the item currently in the loop
          if(isNaN(dig) == false){
             console.log("string")
           }
          else if(isNaN(dig) == true){
            console.log("not string");
            
              var a = i + 1;
              var aDig = previousValue
              var bDig =  parseFloat(expArray[a].trim().toString()); //value after "i"; // value before  "i"
              if (dig == "/"){ //this whole section gets skipped :(
                var sDig = aDig / bDig;
              }

              else if ( dig == "*"){
                var sDig = aDig * bDig;
              }
              else if ( dig == "+"){
                var sDig = aDig + bDig;
                
              }
              else if( dig == "-"){
                var sDig = aDig - bDig;
            }
            previousValue = sDig;
            i++
          }

            }
       alert(previousValue);

        ```

我的if语句和else if语句未执行，但是没有错误

1 个答案: