Algorithm

  1. Input: Take a number as input.

  2. Check if the number is zero:

    • If the number is equal to zero, display "The number is zero" and end the program.
    • If not, proceed to the next step.

  3. Check if the number is positive:

    • If the number is greater than zero, display "The number is positive" and end the program.
    • If not, proceed to the next step.

  4. Check if the number is negative:

    • If the number is less than zero, display "The number is negative" and end the program.
    • If not, the number is not zero, positive, or negative (this should not happen in a typical number system).

 

Code Examples

#1 Code Example- Check Number Type with if...else if...else

Code - Javascript Programming

// program that checks if the number is positive, negative or zero
// input from the user
const number = parseInt(prompt("Enter a number: "));

// check if number is greater than 0
if (number > 0) {
    console.log("The number is positive");
}

// check if number is 0
else if (number == 0) {
  console.log("The number is zero");
}

// if number is less than 0
else {
     console.log("The number is negative");
}
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Output

x
–
+
cmd
Enter a number: 0
The number is zero.

#2 Code Example- Check Number Type with nested if...else

Code - Javascript Programming

// check if the number is positive, negative or zero
const number = prompt("Enter a number: ");

if (number >= 0) {
    if (number == 0) {
        console.log("The number is zero");
    } else {
        console.log("The number is positive");
    }
} else {
    console.log("The number is negative");
}
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Output

x
–
+
cmd
Enter a number: 0
You entered number zero
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Demonstration

Javascript Programing Example to Check if a number is Positive, Negative, or Zero-DevsEnv

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