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I need prompt the visitor for an integer between 1 and 100 and to continue prompting until a valid number is entered.
Here is what I have:
<script>
var number = parseInt(prompt("Please enter a number from 1 to 100", ""));
if (number < 100) {
document.write("Your number (" + number + ") is matches requirements", "");
} else if (isNaN(number)) {
parseInt(prompt("It is not a number. Please enter a number from 1 to 100", ""));
} else {
parseInt(prompt("Your number (" + number + ") is above 100. Please enter a number from 1 to 100", ""));
}
</script>
It recognizes the number but fails to re-ask when the number is wrong. Can you please help me and explain what you added?
Thank you very much.
267
Something like this should do the trick:
do{
var selection = parseInt(window.prompt("Please enter a number from 1 to 100", ""), 10);
}while(isNaN(selection) || selection > 100 || selection < 1);
Here's a recursive approach:
var number = (function ask() {
var n = prompt('Number from 1 to 100:');
return isNaN(n) || +n > 100 || +n < 1 ? ask() : n;
}());
Another approach:
<html>
<head> </head>
<body onload="promptForNumber();">
<script>
function promptForNumber( text)
{
if(text == '' ){
text = "Please enter a number from 1 to 100";
}
var number = parseInt(window.prompt(text, ""));
checkNumber(number);
}
function checkNumber(number){
if (number <= 100 && number >= 1) {
document.write("Your number (" + number + ") matches requirements", "");
} else if (isNaN(number)) {
promptForNumber("It is not a number. Please enter a number from 1 to 100", "");
} else {
promptForNumber("Your number (" + number + ") is not between 1 and 100", "");
}
}
</script>
</body>
</html>
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