トップに関する質問 JavaScriptで取得した式を計算したい（四則演算のみ）

編集履歴

質問編集履歴

levelrr == sikilong - 1の時にsikipb = ""になる記述を追加。

2017/01/06 01:34

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ko20vonobird

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@@ -250,6 +250,12 @@
         sikipb = siki.substring(levelrr, sikilong - 1);
+        if (levelrr == sikilong - 1){
+            sikipb = "";
+        }
         if (siki.charAt(levelrl) == sisoku[2]) { //t
             en = a * b;

//tの上のlevelrr \+ 1をlevelrrに修正

2017/01/06 01:34

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ko20vonobird

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@@ -248,7 +248,7 @@
         b = siki.substring(levellr + 1, levelrr);
-        sikipb = siki.substring(levelrr + 1, sikilong - 1);
+        sikipb = siki.substring(levelrr, sikilong - 1);
         if (siki.charAt(levelrl) == sisoku[2]) { //t

//sの下のsikilongをsikilong - 1に修正

2017/01/06 01:25

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ko20vonobird

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@@ -248,7 +248,7 @@
         b = siki.substring(levellr + 1, levelrr);
-        sikipb = siki.substring(levelrr + 1, sikilong);
+        sikipb = siki.substring(levelrr + 1, sikilong - 1);
         if (siki.charAt(levelrl) == sisoku[2]) { //t

sikipaが""になる記述を追加

2017/01/06 01:20

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ko20vonobird

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@@ -260,6 +260,12 @@
         } //t
+        if (levelll == 0){
+            sikipa = "";
+        }
         siki = sikipa + en + sikipb;
         sikilong = siki.length;

a = siki\.substring\(levelll, levelrl\);をa = siki\.substring\(levelll, levelrl - 1\);に修正

2017/01/06 01:17

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ko20vonobird

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@@ -204,7 +204,7 @@
         } //n
-        a = siki.substring(levelll, levelrl);
+        a = siki.substring(levelll, levelrl - 1);
         sikipa = siki.substring(0, levelll);

//lの上のcntd\+1をcntdに修正

2017/01/06 01:12

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ko20vonobird

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@@ -182,7 +182,7 @@
                 if (siki.charAt(cntd) == sisoku[cntnumb]) { //l
-                    var levelll = cntd + 1;
+                    var levelll = cntd;
                     break;

×÷のところで抜けていた×÷が無いときにbreakする記述を追加。

2017/01/06 01:09

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ko20vonobird

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@@ -140,6 +140,12 @@
         } //5
+        if (kakerupo == -1 && warupo == -1) {
+            break;
+        }
         if (kakerupo != -1 && warupo != -1) { //8
             if (kakerupo > warupo) { //9

説明の修正および新たな問題の記述

2017/01/06 00:59

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ko20vonobird

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@@ -18,6 +18,8 @@
 乗除計算では値が不自然なものに、和と差の計算では結果に"NaN"が含まれかつ式も右にそのまま出てきます。
+三項以上の掛け算でNaNが出現します。
 ```
@@ -392,8 +394,6 @@
 デバッグも粗方行いました。
-※掛け算に関して問題が無くなりました。
 ###補足情報(言語/FW/ツール等のバージョンなど)

//sの下の\(levellr\+1を\(levelrr\+1に修正

2017/01/05 15:45

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ko20vonobird

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@@ -240,7 +240,7 @@
         b = siki.substring(levellr + 1, levelrr);
-        sikipb = siki.substring(levellr + 1, sikilong);
+        sikipb = siki.substring(levelrr + 1, sikilong);
         if (siki.charAt(levelrl) == sisoku[2]) { //t
@@ -390,6 +390,10 @@
 コードを見たらわかるかと思いますが、括弧がちゃんと対応しているか英数字をふって確かめたりしました。
+デバッグも粗方行いました。
+※掛け算に関して問題が無くなりました。
 ###補足情報(言語/FW/ツール等のバージョンなど)

説明の改善

2017/01/05 15:42

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ko20vonobird

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@@ -4,7 +4,7 @@
 HTMLのフォームから「式」を取得し、四則演算記号を判別して演算の順番通りに計算をこなしていくということを実現したいです。
-仕組みとしては、四則演算子を一つずつ潰していく感じになります。
+仕組みとしては、四則演算子を一つずつ潰していく感じになります。今対応させるのは自然数のみです。
 最終的に結果が全て計算されたものになるようなプログラムを目指しています。

//4の少し上のlevelrlをsiki\.charAt\(levelrl\)に修正

2017/01/05 15:27

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ko20vonobird

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@@ -242,11 +242,11 @@
         sikipb = siki.substring(levellr + 1, sikilong);
-        if (levelrl == sisoku[2]) { //t
+        if (siki.charAt(levelrl) == sisoku[2]) { //t
             en = a * b;
-        } else if (levelrl == sisoku[3]) { //t
+        } else if (siki.charAt(levelrl) == sisoku[3]) { //t
             en = a / b;

=が抜けていたところを修正

2017/01/05 15:26

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ko20vonobird

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@@ -242,7 +242,7 @@
         sikipb = siki.substring(levellr + 1, sikilong);
-        if (levelrl = sisoku[2]) { //t
+        if (levelrl == sisoku[2]) { //t
             en = a * b;
@@ -300,7 +300,7 @@
             } //3
-            if (middle = -1) {
+            if (middle == -1) {
                 break;
@@ -344,7 +344,7 @@
                 en = a + b;
-            } else if (siki.charAt(middle) = sisoku[1]) {
+            } else if (siki.charAt(middle) == sisoku[1]) {
                 en = a - b;

編集・追記依頼に基づき、整形しました。

2017/01/05 15:13

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ko20vonobird

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@@ -26,361 +26,361 @@
 ```JavaScript
-function keisan() {//a
-/*try{*/
-var chk1 = 0
-var str = document.siki.mainsiki.value;
-var strlong = str.length;
-for (var cnt=0 ; cnt<10 ; cnt++){//b
-if (str.indexOf(cnt,0) != 0){//c
-chk1++
-}//c
-}//b
-if (chk1>9){//d
-alert("最初の文字は数字にしてください");
-return;
-}//d
-var siki = str;
-var sikilong = siki.length;
-var sisoku = new Array();
-sisoku[0] = '+';
-sisoku[1] = '-';
-sisoku[2] = '*';
-sisoku[3] = '/';
-var sisokunum = 0;
-for (var cntstrnum=0 ; cntstrnum<sikilong ; cntstrnum++){//e
-var chk = siki.charAt(cntstrnum);
-for (var cnta = 0 ; cnta<4 ; cnta++){//f
-if (chk == sisoku[cnta]){//g
-sisokunum = sisokunum + 1;
-}//g
-}//f
-}//e
-if (sisokunum == 0){//h
-alert("答え:" + siki);
-return;
-}//h
-//×÷の計算
-var nisokukw = 0;
-for (var cntnuma=0 ; cntnuma<sikilong; cntnuma++){//1
-var chk = siki.charAt(cntnuma);
-for (var cntb=2 ; cntb<4 ; cntb++){//2
-if (chk == sisoku[cntb]){//3
-nisokukw = nisokukw + 1;
-}//3
-}//2
-}//1
-var kakerupo = -1;
-var warupo = -1;
-for (var cntmaina=0 ; cntmaina<=nisokukw ; cntmaina++){//4
-for (var cntc=2 ; cntc<4 ; cntc++){//5
-if (siki.indexOf(sisoku[cntc]) != -1){//6
-if (cntc == 2){//7
-kakerupo = siki.indexOf(sisoku[cntc]);
-}else if (cntc == 3){//7
-warupo = siki.indexOf(sisoku[cntc]);
-}//7
-}//6
-}//5
-if (kakerupo != -1 && warupo != -1){//8
-if (kakerupo > warupo){//9
-var levelrl = kakerupo;
-}else{//9
-var levelrl = warupo;
-}//9
-}else if (kakerupo != -1){//8
-var levelrl = kakerupo;
-}else if (warupo != -1){//8
-var levelrl = warupo;
-}//8
-var levelll = -1;
-for (var cntd=levelrl-1 ; cntd>=0 ; cntd--){//i
-if (levelll != -1){//j
-break;
-}//j
-for (var cntnumb=0 ; cntnumb<4 ; cntnumb++){//k
-if (siki.charAt(cntd) == sisoku[cntnumb]){//l
-var levelll = cntd + 1;
-break;
-}//l
-if (levelll != -1){//m
-break;
-}//m
-}//k
-}//i
-if (levelll == -1){//n
-levelll = 0;
-}//n
-a = siki.substring(levelll,levelrl);
-sikipa = siki.substring(0,levelll);
-var levellr = levelrl;
-var levelrr = -1;
-for (var cnte=levellr+1 ; cnte<sikilong ; cnte++){//o
-for (var cntnumc=0 ; cntnumc<4 ; cntnumc++){//p
-if (siki.charAt(cnte) == sisoku[cntnumc]){//q
-levelrr = siki.charAt(cnte);
-break;
-}//q
-if (levelrr != -1){//r
-break;
-}//r
-}//p
-if (levelrr != -1){///u
-break;
-}///u
-}//o
-if (levelrr == -1){//s
-levelrr = sikilong;
-}//s
-b = siki.substring(levellr+1,levelrr);
-sikipb = siki.substring(levellr+1,sikilong);
-if (levelrl = sisoku[2]){//t
-en = a * b;
-}else if (levelrl == sisoku[3]){//t
-en = a / b;
-}//t
-siki = sikipa + en + sikipb;
-sikilong = siki.length;
-}//4
-//+-の計算
-var nisokuth = 0;
-for (var cntf=0 ; cntf<=sikilong ; cntf++){
-for (var cntnumd=0; cntnumd<4 ; cntnumd++){
-if (sisoku[cntnumd] == siki.charAt(cntf)){
-nisokuth++;
-}
-}
-}
-for (var cntmainb=0 ; cntmainb<=nisokuth; cntmainb++){//1
-var middle = -1;
-for (var cntg=0 ; cntg<sikilong ; cntg++){//2
-for (var cntnume=0 ; cntnume<2 ; cntnume++){//3
-if (sisoku[cntnume] == siki.charAt(cntg)){//4
-var middle = cntg;
-break;
-}//4
-if (middle != -1){//5
-break;
-}//5
-}//3
-if (middle = -1){
-break;
-}
-var lrright = -1;
-var llleft = 0;
-var llright = middle - 1;
-var lrleft = middle + 1;
-for (var cntaa = lrleft ; cntaa < sikilong - lrleft + 1 ; cntaa++){
-for (var cntnumaa = 0 ; cntnumaa < 2 ; cntnumaa++){
-if (sisoku[cntnumaa] == siki.charAt(cntaa)){
-lrright = cntaa - 1;
-break;
-}
-}
-if (lrright == -1){
-lrlight = sikilong;
-}
-}
-var a = siki.substring(llleft,llright);
-var b = siki.substring(lrleft,lrright);
-if (siki.charAt(middle) == sisoku[0]){
-en = a + b;
-}else if (siki.charAt(middle) = sisoku[1]){
-en = a - b;
-}
-var sikipb = substring(lrright,sikilong);
-siki = en + sikipb;
-}//2
-if (middle == -1){
-alert("答え:" + siki);
-return;
-}
-}//1
-/*}catch(e){
-alert("式が不適合もしくはエラーです。");
-return;
-}
-finally{
-return;
-}*/
-}//a
+function keisan() { //a
+    /*try{*/
+    var chk1 = 0
+    var str = document.siki.mainsiki.value;
+    var strlong = str.length;
+    for (var cnt = 0; cnt < 10; cnt++) { //b
+        if (str.indexOf(cnt, 0) != 0) { //c
+            chk1++
+        } //c
+    } //b
+    if (chk1 > 9) { //d
+        alert("最初の文字は数字にしてください");
+        return;
+    } //d
+    var siki = str;
+    var sikilong = siki.length;
+    var sisoku = new Array();
+    sisoku[0] = '+';
+    sisoku[1] = '-';
+    sisoku[2] = '*';
+    sisoku[3] = '/';
+    var sisokunum = 0;
+    for (var cntstrnum = 0; cntstrnum < sikilong; cntstrnum++) { //e
+        var chk = siki.charAt(cntstrnum);
+        for (var cnta = 0; cnta < 4; cnta++) { //f
+            if (chk == sisoku[cnta]) { //g
+                sisokunum = sisokunum + 1;
+            } //g
+        } //f
+    } //e
+    if (sisokunum == 0) { //h
+        alert("答え:" + siki);
+        return;
+    } //h
+    //×÷の計算
+    var nisokukw = 0;
+    for (var cntnuma = 0; cntnuma < sikilong; cntnuma++) { //1
+        var chk = siki.charAt(cntnuma);
+        for (var cntb = 2; cntb < 4; cntb++) { //2
+            if (chk == sisoku[cntb]) { //3
+                nisokukw = nisokukw + 1;
+            } //3
+        } //2
+    } //1
+    var kakerupo = -1;
+    var warupo = -1;
+    for (var cntmaina = 0; cntmaina <= nisokukw; cntmaina++) { //4
+        for (var cntc = 2; cntc < 4; cntc++) { //5
+            if (siki.indexOf(sisoku[cntc]) != -1) { //6
+                if (cntc == 2) { //7
+                    kakerupo = siki.indexOf(sisoku[cntc]);
+                } else if (cntc == 3) { //7
+                    warupo = siki.indexOf(sisoku[cntc]);
+                } //7
+            } //6
+        } //5
+        if (kakerupo != -1 && warupo != -1) { //8
+            if (kakerupo > warupo) { //9
+                var levelrl = kakerupo;
+            } else { //9
+                var levelrl = warupo;
+            } //9
+        } else if (kakerupo != -1) { //8
+            var levelrl = kakerupo;
+        } else if (warupo != -1) { //8
+            var levelrl = warupo;
+        } //8
+        var levelll = -1;
+        for (var cntd = levelrl - 1; cntd >= 0; cntd--) { //i
+            if (levelll != -1) { //j
+                break;
+            } //j
+            for (var cntnumb = 0; cntnumb < 4; cntnumb++) { //k
+                if (siki.charAt(cntd) == sisoku[cntnumb]) { //l
+                    var levelll = cntd + 1;
+                    break;
+                } //l
+                if (levelll != -1) { //m
+                    break;
+                } //m
+            } //k
+        } //i
+        if (levelll == -1) { //n
+            levelll = 0;
+        } //n
+        a = siki.substring(levelll, levelrl);
+        sikipa = siki.substring(0, levelll);
+        var levellr = levelrl;
+        var levelrr = -1;
+        for (var cnte = levellr + 1; cnte < sikilong; cnte++) { //o
+            for (var cntnumc = 0; cntnumc < 4; cntnumc++) { //p
+                if (siki.charAt(cnte) == sisoku[cntnumc]) { //q
+                    levelrr = siki.charAt(cnte);
+                    break;
+                } //q
+                if (levelrr != -1) { //r
+                    break;
+                } //r
+            } //p
+            if (levelrr != -1) { ///u
+                break;
+            } ///u
+        } //o
+        if (levelrr == -1) { //s
+            levelrr = sikilong;
+        } //s
+        b = siki.substring(levellr + 1, levelrr);
+        sikipb = siki.substring(levellr + 1, sikilong);
+        if (levelrl = sisoku[2]) { //t
+            en = a * b;
+        } else if (levelrl == sisoku[3]) { //t
+            en = a / b;
+        } //t
+        siki = sikipa + en + sikipb;
+        sikilong = siki.length;
+    } //4
+    //+-の計算
+    var nisokuth = 0;
+    for (var cntf = 0; cntf <= sikilong; cntf++) {
+        for (var cntnumd = 0; cntnumd < 4; cntnumd++) {
+            if (sisoku[cntnumd] == siki.charAt(cntf)) {
+                nisokuth++;
+            }
+        }
+    }
+    for (var cntmainb = 0; cntmainb <= nisokuth; cntmainb++) { //1
+        var middle = -1;
+        for (var cntg = 0; cntg < sikilong; cntg++) { //2
+            for (var cntnume = 0; cntnume < 2; cntnume++) { //3
+                if (sisoku[cntnume] == siki.charAt(cntg)) { //4
+                    var middle = cntg;
+                    break;
+                } //4
+                if (middle != -1) { //5
+                    break;
+                } //5
+            } //3
+            if (middle = -1) {
+                break;
+            }
+            var lrright = -1;
+            var llleft = 0;
+            var llright = middle - 1;
+            var lrleft = middle + 1;
+            for (var cntaa = lrleft; cntaa < sikilong - lrleft + 1; cntaa++) {
+                for (var cntnumaa = 0; cntnumaa < 2; cntnumaa++) {
+                    if (sisoku[cntnumaa] == siki.charAt(cntaa)) {
+                        lrright = cntaa - 1;
+                        break;
+                    }
+                }
+                if (lrright == -1) {
+                    lrlight = sikilong;
+                }
+            }
+            var a = siki.substring(llleft, llright);
+            var b = siki.substring(lrleft, lrright);
+            if (siki.charAt(middle) == sisoku[0]) {
+                en = a + b;
+            } else if (siki.charAt(middle) = sisoku[1]) {
+                en = a - b;
+            }
+            var sikipb = substring(lrright, sikilong);
+            siki = en + sikipb;
+        } //2
+        if (middle == -1) {
+            alert("答え:" + siki);
+            return;
+        }
+    } //1
+    /*}catch(e){
+    alert("式が不適合もしくはエラーです。");
+    return;
+    }
+    finally{
+    return;
+    }*/
+} //a
 ```