Question

Write a program to enter any Number and check whether it is negative or positive..

plz tell me friends....​

Answer 1

Explanation:

function isPositive(num) {

// if something is true return true; else return false is redundant.

return num >= 0;

}

// when you want to keep doing something until a condition is met,

// particularly with user input, consider a while(true) loop:

var num;

while (true) {

num = prompt("Enter a number");

// check for null here

if (num === null) {

alert("No number entered. Try again.");

continue; // return to the start of the loop

}

num = parseInt(num, 10); // second argument is NOT optional

if (isNaN(num)) {

alert("Invalid number entered. Try again.");

continue;

}

// once we have a valid result...

break;

}

// the loop will continue forever until the `break` is reached. Once here...

alert(isPositive(num));