fix subtraction, enable multiple numbers with addition of last numbers, remove zeros from result

src/Subtraction.js

@@ -97,6 +97,8 @@ function Subtraction() {
     let nosLeft = imdtResIdx + 1;
     let carryText = "Übertrag = ";
     let carryOffset = 0;
+    let firstDigit = 0;
+    let digit = 0;
 
     if(typeof numbers === "object" && imdtResIdx !== -1){
       if(typeof imdtResIdx === "undefined" || imdtResIdx === null){
@@ -109,29 +111,42 @@ function Subtraction() {
         carryOffset = 1;
       }
 
-      for (let n in numbers){ // iterate numbers
-        if(nosLeft === 1 && carryArr[0] === "0"){
-          nosLeft = 0;
-          imdtResIdx = -1;
-          handleResChange(" ", 0)
-          return <></>
-        }
-        let digit = numbers[parseInt(n)][imdtResIdx];
-        if(digit === "" || digit === "&nbsp;"){
-          digit = 0;
-        }
-        labelText += digit;
+      if(numbers.length>2){
+        labelText = "("
+      }
 
-        if (parseInt(n) === numbers.length - 1){
-          if(carryArr[imdtResIdx+carryOffset]!=="undefind" && carryArr[imdtResIdx+carryOffset] > 0){
-            labelText += " + " + carryArr[imdtResIdx+carryOffset].toString();
-          }
-          labelText += " = ";
+      for (let n in numbers){ // iterate numbers
+        if(parseInt(n)===0){
+          firstDigit = numbers[parseInt(n)][imdtResIdx];
         }else{
-          labelText += " - ";
+          if(nosLeft === 1 && carryArr[0] === "0"){
+            nosLeft = 0;
+            imdtResIdx = -1;
+            handleResChange("&nbsp;", 0)
+            return <></>
+          }
+          digit = numbers[parseInt(n)][imdtResIdx];
+          if(digit === "" || digit === "&nbsp;"){
+            digit = 0;
+          }
+          labelText += digit;
+
+          if (parseInt(n) === numbers.length - 1){
+            if(carryArr[imdtResIdx+carryOffset]!=="undefind" && carryArr[imdtResIdx+carryOffset] > 0){
+              labelText += " + " + carryArr[imdtResIdx+carryOffset].toString();
+            }
+            if(numbers.length>2){
+              labelText += ")";
+            }
+          }else{
+            labelText += " + ";
+          }
         }
       }
 
+      labelText += " + wie viel = " + firstDigit
+      labelText = labelText.replace(/&nbsp;/g, "0")
+
       if(carryArr[imdtResIdx+carryOffset] > -1 || imdtResIdx === noOfDigits-1){
         imdtRes = -1;
         imdtResIdx = imdtResIdx - 1;
@@ -189,20 +204,28 @@ function Subtraction() {
       let idxCarry = carries.length - i - 1;
 
       let realDigitRes = 0;
+      let firstDigit = 0;
       for (let j=0; j<numbers.length; j++) {
-        let no = numbers[j][idxNumbers];
+        if(parseInt(j)===0){
+          firstDigit = numbers[parseInt(j)][idxNumbers];
+          if(firstDigit==="" | firstDigit==="&nbsp;"){
+            firstDigit = 0;
+          }
+        }else{
+          let no = numbers[j][idxNumbers];
 
-        if (j === 0){
-          realDigitRes = parseInt(no);
-        }
-        else if (no!=="." && no!=="&nbsp;"){
-          trueNumbers = true;
-          realDigitRes -= parseInt(no);
-        }
+          if (j === 0){
+            realDigitRes = parseInt(no) | 0;
+          }
+          else if (no!=="." && no!=="&nbsp;"){
+            trueNumbers = true;
+            realDigitRes += parseInt(no);
+          }
 
-        text += no
-        if (j<numbers.length-1){
-          text += " - "
+          text += no
+          if (j<numbers.length-1){
+            text += " + "
+          }
         }
       }
 
@@ -222,21 +245,24 @@ function Subtraction() {
 
       // add carry only if > 0
       if (carries[idxCarry]!=="0"){
-        realDigitRes -= parseInt(carries[idxCarry]);
-        text += " - " + carries[idxCarry] // + " Übertrag"
+        realDigitRes += parseInt(carries[idxCarry]);
+        text += " + " + carries[idxCarry] // + " Übertrag"
       }
-      console.log(realDigitRes)
-      let realCarry = Math.abs(parseInt(realDigitRes/10)).toString()
-      realDigitRes = (realDigitRes % 10)
+      let realCarry = Math.abs(parseInt(realDigitRes/10));
+      realDigitRes = ((firstDigit - realDigitRes) % 10);
+
       if (realDigitRes < 0){
-        realDigitRes = realDigitRes + 10
+        realDigitRes = realDigitRes + 10;
+        realCarry += 1;
       }
+
+      realCarry = realCarry.toString();
       realDigitRes = realDigitRes.toString()
-      text += " = "
+      text += " und "
 
       if (trueNumbers){
-        text += resArr[idxNumbers]
-        text += " und " + carries[idxCarry-1] + " Übertrag "
+        text += resArr[idxNumbers] + " = " + firstDigit
+        text += " mit " + carries[idxCarry-1] + " Übertrag "
         text = text.replace(/&nbsp;/g, "0")
         text += resArr[idxNumbers]===realDigitRes && carries[idxCarry-1]===realCarry ? "(Richtig)" : "(Falsch)";
         stepsGridCopy.push({step: text});
@@ -253,12 +279,25 @@ function Subtraction() {
   const finishCalculation = () => {
     setShowAlert(false);
     document.getElementById("idmtResultSteps").innerHTML = "";
-    let resCalc = resArr.filter(n => n !== "&nbsp;").join("");
+
+    // remove zeros at the beginning
+    let res = [];
+    let beginNr = false;
+    for(let r in resArr){
+      let digit = resArr[r];
+      if(digit==="&nbsp;"){
+        continue
+      }
+      if(digit!=="0" | beginNr | parseInt(r)===resArr.length-1){
+        beginNr = true;
+        res.push(digit)
+      }
+    }
+    let resCalc = res.join("");
     setResultsGrid([{number: resCalc}]);
     resCalc = parseFloat(resCalc);
 
     let message = "";
-    console.log(resCalc, realResult);
     if(resCalc === realResult){
       message = "Richtig!";
     }else{