JavaScript DHTML/Data Type/Number

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Add different type variables together

   <source lang="html4strict">

<html> <head> <title></title> </head> <body> <script type="text/javascript"> var num1 = 1; var num2 = 2; var num3 = 3; var fourthvar = "4"; var name1 = "a"; var name2 = "b"; alert(num1 + num2); alert(num3 + fourthvar); alert(name1 + name2); </script> </body> </html> 


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Calculate circle area/Peri/Calculate sphere volume

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<html> <head> <title>A Simple Page</title> <script language="JavaScript"> function calcArea(){ 

   inpRadius = 3;
   alert(Math.PI * ((inpRadius)*(inpRadius)));

} function calcPeri() { 

   inpRadius = 3;
   alert(2 * Math.PI * (inpRadius));

} function calcVol() { 

   inpRadius = 3;
   alert(Math.PI * ((inpRadius)*(inpRadius)*(inpRadius)) * (4/3));

} </script> </head> <body> <input type="button" value="Calculate circle area" onclick="calcArea();"> <input type="button" value="Calculate circle Peri" onclick="calcPeri();"> <input type="button" value="Calculate sphere volume" onclick="calcVol();"> </body> </html> 


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Calculate the average for integers

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<html> <head> <title>A Simple Page</title> <script language="JavaScript"> function calcAvg(){ 

   var inpNum1 = 1;
   var inpNum2 = 2;
   var inpNum3 = 3;
   var inpNum4 = 4;
   numAvg = doCalcAvg(inpNum1, inpNum2, inpNum3, inpNum4);
   alert("The average is: " + numAvg);

} function doCalcAvg(inpNum1, inpNum2, inpNum3, inpNum4) { 

   var ans;
   ans = (Number(inpNum1) + Number(inpNum2) + Number(inpNum3) + Number(inpNum4)) / 4;
   return (ans);

} </script> </head> <body onLoad="calcAvg();"> </body> </html> 


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Check if it is a number and calculate the cubic power

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<html> <head> <script type = "text/javascript"> function cubeme(aNum) { 

   if (aNum == 1) {
       return 1;
   } else {
       return Math.pow(aNum,3);
   }

} </script> </head> <body> <script type = "text/javascript"> var theNum = 2; var finalNum = cubeme(theNum); if (isNaN(finalNum)) { 

   alert("Not a number.");

} else { 

   alert(finalNum);

} </script> </body> </html> 


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Compare the value for integer numbers

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<HTML> <BODY> <SCRIPT language="JavaScript"> var num1 = 0; var num2 = 0; if(num1 == num2) { 

window.alert("True");

} else { 

window.alert("False");

} </SCRIPT> </BODY> </HTML> 


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Convert a Number to a Exponential format

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<html> <body> <button onclick="var myNum = new Number(100); alert(myNum.toExponential(1));"> Number toExponential </button> </body> </html> 



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Convert a number to a precision

   <source lang="html4strict">

<html> <body> <button onclick="var myNum = new Number(100); alert(myNum.toPrecision(1));"> Number toPrecision </button> </body> </html> 



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Convert a number to string by append empty string to it

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<html> <head> </head> <body> <script type="text/javascript"> 

 function numToString(number) {
   number += "";
   return number;
 }
 var number = 100;
 alert(typeof number);
 number = numToString(number);
 alert(typeof number);

</script> </body> </html> 


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Convert Fahrenheit to Celsius

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<html> <head> <title>A Simple Page</title> <script language="JavaScript"> function inputFah(){ 

   var fah = 100;
   ansCel = doCelCalc(fah);
   alert(fah + " Degrees Fahrenheit is " + ansCel + " Degrees Celsius");

} function doCelCalc(fah){ 

   var ans = ((Number(fah) - 32) / 1.8);
   return (ans);

} </script> </head> <body> 

   <input type="button" value="Convert Fahrenheit to Celsius" onClick="inputFah();">

</body> </html> 


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Convert from Celsius to Fahrenheit

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<html> <head> <title>A Simple Page</title> <script language="JavaScript"> function inputCels(){ 

   var cels = 100;
   ansFah = doFahCalc(cels);
   alert(cels + " Degrees Celsius is " + ansFah + " Degrees Fahrenheit");

} function doFahCalc(cels){ 

   var ans = ((1.8 * Number(cels)) + 32);
   return (ans);

} </script> </head> <body> <input type="button" value="Convert Celsius to Fahrenheit" onClick="inputCels();"> </body> </html> 


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Declare float point number, boolean value and null value

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<HTML> <BODY> <SCRIPT language="JavaScript">

</SCRIPT> </BODY> </HTML> 


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Fix a number

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<html> <body> <button onclick="var myNum = new Number(100.22); alert(myNum.toFixed(1));"> Number toFixed </button> </body> </html> 



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Hexadecimal Numbers

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<html> <head> <script type = "text/javascript"> var h = 0xe; var i = 0x2; var j = h * i; document.write(j); </script> </head> </html> 


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Integer math calculation

   <source lang="html4strict">

<HTML> <BODY> <SCRIPT language="JavaScript"> var intValue=200; document.write(intValue+"
"); intValue += 200; document.write(intValue+"
"); intValue = intValue-50; document.write(intValue+"
"); intValue = intValue*0; document.write(intValue+"
"); intValue = intValue + 500; document.write(intValue+"
"); intValue -= 80; document.write(intValue+"
"); </SCRIPT> </BODY> </HTML> 


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Read a number and compare its value

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<html> <head> 

   <title>An If Example</title>

</head> <body> <script type = "text/javascript" > var inputNum = prompt("Please enter a number below 100:"); if (inputNum > 99) { 

   document.write("That number, " + inputNum + ", is not below 100.");

} </script> </body> </html> 


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Using Binary Flags

   <source lang="html4strict">

<html> <head> <title>Using Binary Flags</title> <script type="text/javascript"> var FIELD_A = 0x1; // 00001 var FIELD_B = 0x2; // 00010 var FIELD_C = 0x4; // 00100 var FIELD_D = 0x8; // 01000 var FIELD_E = 0x10; // 10000 var fieldsSet = FIELD_A | FIELD_C | FIELD_E; if ((fieldsSet & FIELD_A) && (fieldsSet & FIELD_C)) { 

  document.write("Fields A and C are set");

} </script> </head> </body> </html> 


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Источник — «http://wbex.ru/index.php?title=JavaScript_DHTML/Data_Type/Number&oldid=1755»