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Christopher McGurn
Full Stack JavaScript Techdegree Student 4,771 PointsSharing my solution
Super happy with this result! Figured I'd show my solution to share my approach to certain parts of the task.
alert('It\'s time to do some math!');
const firstNumberInput = prompt('Enter a number:');
const firstNumber = parseFloat(firstNumberInput);
const secondNumberInput = prompt('Enter another number:');
const secondNumber = parseFloat(secondNumberInput);
if (firstNumber && secondNumber) {
const message = `
<h1>Math with the numbers ${firstNumber} and ${secondNumber}</h1>
${firstNumber} + ${secondNumber} = ${firstNumber + secondNumber}<br>
${firstNumber} * ${secondNumber} = ${firstNumber * secondNumber}<br>
${firstNumber} / ${secondNumber} = ${firstNumber / secondNumber}<br>
${firstNumber} - ${secondNumber} = ${firstNumber - secondNumber}<br>
`;
document.write(message);
} else {
alert('Please enter two valid numbers.');
}
3 Answers
Steven Parker
231,248 PointsUsing a template literal is a logical and effectively equivalent output method.
But combining numbers with the Boolean "and" operator (&&) is not an effective way to test for number validity. That's what the "isNaN" function is for.
To see the problem, try using 0 as one of the "valid numbers".
Christopher McGurn
Full Stack JavaScript Techdegree Student 4,771 PointsOh! I think I see what the problem is there. A string input value of '0' is considered a falsy value thus returns false in the condition. Is this correct?
Steven Parker
231,248 PointsAny non-empty string would be considered "truthy", including "0".
But they aren't strings at that point, they have been converted to numbers with "parseFloat". Then the "and" operator converts the terms into Boolan, and a 0 value translates to false.
Christopher McGurn
Full Stack JavaScript Techdegree Student 4,771 PointsThank you for the information!