92 lines
3.3 KiB
HTML
92 lines
3.3 KiB
HTML
<html>
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<head>
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<title>Example 7.3</title>
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<script>
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function quotient(x,y)
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{
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illegal = "Illegal division operation";
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if (y != 0)
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return x/y;
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else
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return illegal;
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}
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function divideIt()
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{
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var divTop = parseFloat(prompt("Enter the divisor:"));
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var divBottom = parseFloat(prompt("Enter the dividend:"));
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document.getElementById('division').innerHTML = (divTop + " divided by " + divBottom);
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var division = quotient(divTop, divBottom);
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if (isNaN(division))
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division = "illegal division operation";
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else
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division = division.toFixed(2);
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document.getElementById('result').innerHTML = division;
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}
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function getMileage()
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{
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var miles = parseFloat(prompt("How many miles did your drive on this trip?"));
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var gallons = parseFloat(prompt("How many gallons of gas did you use?"));
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var trip = quotient(miles, gallons);
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if (isNaN(trip))
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{
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trip = "illegal division operation";
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document.getElementById('mileage').innerHTML = ("Cannot complete the calculation. " + trip);
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}
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else
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{
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trip = trip.toFixed(1);
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document.getElementById('mileage').innerHTML = ("Your mileage for this trip was " + trip + " mpg.");
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}
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}
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function getBMI()
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{
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var feet = parseFloat(prompt("How tall are you? Enter your height in feet first:"));
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var inches = parseFloat(prompt("How many inches over " + feet + " feet are you?"));
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var height = (feet * 12 + inches);
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var hInches= height * height;
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var weight = parseFloat(prompt("What is your weight in pounds? You may include a partial pound, like 128.5 lbs, for example."));
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document.getElementById('height').innerHTML = (height.toFixed(2));
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document.getElementById('weight').innerHTML = (weight.toFixed(2));
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var bmi = (quotient(weight, hInches) * 703);
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if (isNaN(bmi))
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{
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bmi = "illegal division operation";
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document.getElementById('bmi').innerHTML = ("cannot complete the calculation. " + bmi);
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}
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else
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{
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bmi = bmi.toFixed(2);
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document.getElementById('bmi').innerHTML = (" " + bmi);
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}
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}
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</script>
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<style type="text/css">
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<!--
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body {
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margin: 5%;
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}
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-->
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</style>
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</head>
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<body>
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<h2>Using the quotient() function</h2>
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<div style="width: 80%;">
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<div style="width: 50%; float: left;"><fieldset><legend>Division Problem</legend>
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<input type ="button" onclick="divideIt()" value = "Enter a division problem"></button>
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<h2><span id = "division"> </span></h2>
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<h2>The result is: <span id = "result"> </span></h2></fieldset></div>
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<div style=" width: 50%; float: left;"><fieldset><legend>Gas Mileage</legend>
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<input type ="button" onclick="getMileage()" value = "Find the gas mileage"></button>
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<h2><span id = "mileage"> </span></h2></fieldset></div>
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<div style="clear:both;"></div></div>
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<br />
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<div style="width: 80%;"><fieldset><legend>BMI (Body Mass Index) Calculator</legend>
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<p>The formula to calculate your BMI is your weight in pounds (lbs) divided by your height in inches (in) squared and multiplied by a conversion factor of 703. But don't worry about doing the math! If you enter your weight (lbs) and height (in feet and inches), the program will calculate your BMI.</p>
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<input type ="button" onclick="getBMI()" value = "Calculate your BMI (Body Mass Index)"></button>
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<h3>Your height (in inches): <span id = "height"> </span></h3>
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<h3>Your weight (in pounds): <span id = "weight"> </span></h3>
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<h3>Your BMI: <span id = "bmi"> </span></h3>
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</fieldset></div>
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</body>
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</html>
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