Add files via upload

js operation bug fixed 1

cal.js

@@ -0,0 +1,172 @@
+function init(){
+	var num=document.getElementById("num");
+	 num.value=0;
+	 var num1=0;
+     var num2=0;
+	 num.disabled="disabled";
+	 var fh;
+
+
+ var button=document.getElementsByTagName("input");
+     for (i=0;i<button.length;i++){
+     	button[i].onclick=function numclick(){
+     	 var num=document.getElementById("num");
+     	 var n = num.value;
+     	  if(!isNaN(this.value)){
+            if(num1 == 0)  {
+            if(n == "0"){
+            n=this.value;
+            num.value = n;
+              }else{
+              n = n + this.value;
+              num.value = n;   
+               }
+             }else{
+               if(num2 == "0"){
+                num2 = this.value;
+                num.value = num2;
+               }else{
+                num2 = n + this.value;
+                num.value = num2;
+               }
+             }
+            }
+
+
+           else{
+	        var nonum=this.value;
+	        switch(nonum){
+            case "c":
+            num.value=0;
+            num1=0;
+            num2=0;
+            break;
+            //if the user has already conducted unfinshed calculation, conduct
+            // the previous calculation first
+            case "+":
+
+              operation(fh,num1,num2,num);
+              num1 = num.value;
+               num2 = 0;
+               fh= "+";
+             break;
+            case "-":
+              operation(fh,num1,num2,num);
+
+               num1 = num.value;
+               num2 = 0;
+               fh="-"
+              break;
+            case "*":
+             operation(fh,num1,num2,num);
+
+              num1 = num.value;
+              num2 = 0;
+              fh="*";
+              break;
+            case "/":
+             operation(fh,num1,num2,num);
+
+               num1 = num.value;
+               num2 = 0;
+               fh="/";
+               break;
+
+            case ".":
+             num.value=point(num.value);
+             break;
+            case "←":
+             num.value=back(num.value);
+             break;
+
+            case "+/-":
+            if(num.value != 0){
+             num.value=sign(num.value);}
+             break;
+
+            case "=":
+              operation(fh,num1,num2,num);
+               break;
+	     }  
+        }
+     } 
+    }
+}
+        /* . */
+          function point(n){
+            if(n.indexOf(".")==-1){
+            	  n=n+".";
+            }
+
+            return n;
+          }  
+        /*is null?*/
+         function isNull(n){
+            if(n==0 || n.length==0)
+                return true;
+            else return false;
+
+         }
+
+        /*back*/
+         function back(n){
+            if(!isNull(n)){
+             n=n.substr(0,n.length-1);
+            }
+
+            else n=0;
+            return n;
+         }
+        /* -/+ */
+         function sign(n){
+            if(n.indexOf("-")==-1) {
+                n="-"+n;
+            }
+            else {
+                n=n.substr(1,n.length);
+            }
+            return n;
+         }
+
+         //operation
+          function operation(fh,num1,num2,num){
+             switch(fh){
+              //fix the bug of JS float accuracy
+
+              case "+":
+               if(num1!=0 && num2!=0){ 
+                num.value=((num1*Math.pow(10,8))+(num2*Math.pow(10,8)))/Math.pow(10,8);
+                num1 = num.value;
+                num2 = 0;}
+                break;
+              case "-":
+               if(num1!=0 && num2!=0){ 
+                num.value=((num1*Math.pow(10,8))-(num2*Math.pow(10,8)))/Math.pow(10,8);
+                num1 = num.value;
+                num2 = 0;}
+               break;
+              case "*":
+              if(num1!=0 && num2!=0){
+               num.value=((num1*Math.pow(10,8))*(num2*Math.pow(10,8)))/Math.pow(10,16);
+                num1 = num.value;
+                num2 = 0;
+                       }
+                break;
+              case "/":
+               if(num.value==0){
+                num.value=0;
+                alert("0 cannot be divided!")
+                  }
+                 if(num1!=0 && num2!=0){
+                 num.value=((num1*Math.pow(10,8))/(num2*Math.pow(10,8)));
+                 num1 = num.value;
+                num2 = 0;}
+                 break;
+
+                }
+          }
+
+
+
+
+