CODEWITHSUNDEEP
javascript
Hank Justin Bodden
Hank Justin Bodden

Reputation: 11

Some of my conditions are being overlooked

This small app is to tell how fast a driver was going, when I test this code it only alerts the first condition, no matter what my entry is and this is a serious bug, this is the code I appreciate all help thanks in advance to all

    alert(
        "Welcome this program tells you how fast you were driving your 
         vehicle, in km/h");

var top_speed = parseInt(prompt("How many km/h you was at?"));

if (top_speed >= 60) {
    alert("You were driving at " + top_speed + "km/h thats a normal speed");

} else if (top_speed >= 80) {
    alert("You were driving at " + top_speed + "km/h thats a moderate 
    speed");

} else if (top_speed >= 120) {
    alert("You were driving at " + top_speed + "km/h that is a very high 
    speed");

} else {
    alert("You need to go faster " + top_speed + "km/h is too slow ");
}

Upvotes: 0

Views: 29

Answers (4)

Shidersz
Shidersz

Reputation: 17190

You need to reverse your check conditions:

Just imagine, when you input 140, that value is greater than 60 so the code will enter on the first if condition, and none of the other conditions will be inspected.

alert("Welcome this program tells you how fast you were driving your vehicle, in km/h");

var top_speed = parseInt(prompt("How many km/h you was at?"));

if (top_speed >= 120)
{
    alert("You were driving at " + top_speed + "km/h thats a very high speed");
}
else if (top_speed >= 80)
{
    alert("You were driving at " + top_speed + "km/h thats a moderate speed");
}
else if (top_speed >= 60)
{
    alert("You were driving at " + top_speed + "km/h that is a normal speed");
}
else
{
    alert("You need to go faster " + top_speed + "km/h is too slow ");
}

Upvotes: 0

user10957435
user10957435

Reputation:

In addition to the good answers already here (they are the true answer), I think I should also mention this in case someone else has a similar problem.

Else if is only executed if the first condition is false. That is to say, a string of else ifs will ONLY execute the FIRST true condition. If none exists, only then will it execute the else or, if none exists, do nothing.

Upvotes: 0

Maheer Ali
Maheer Ali

Reputation: 36564

This is because the first condition top_speed >= 60 is true whenever the other two conditions top_speed >= 80 and top_speed >= 120 are true.Whenever any of conditions will be true it will not check others which are below that. You should change the order. 

var top_speed = parseInt(prompt("How many km/h you was at?"));

if (top_speed >= 120) {
    alert("You were driving at " + top_speed + "km/h that is a very high speed");

}
else if (top_speed >= 80) {
    alert("You were driving at " + top_speed + "km/h thats a moderate speed");
}  
else if (top_speed >= 60) {
    alert("You were driving at " + top_speed + "km/h thats a normal speed");

} 
 else {
    alert("You need to go faster " + top_speed + "km/h is too slow ");
}

Upvotes: 0

Marvin
Marvin

Reputation: 14255

The statements are evaluated from top to bottom. As 80 and 120 are both also >= 60, the first condition will always match for values of 60 and above.

Simply switch the order:

if (top_speed >= 120) {
    alert("You were driving at " + top_speed + "km/h that is a very high 
    speed");

} else if (top_speed >= 80) {
    alert("You were driving at " + top_speed + "km/h thats a moderate 
    speed");

} else if (top_speed >= 60) {
    alert("You were driving at " + top_speed + "km/h thats a normal speed");

} else {
    alert("You need to go faster " + top_speed + "km/h is too slow ");
}

An alternative would be to be more specific in your conditions, i.e. also include an upper bound:

if (top_speed >= 60 && top_speed < 80) {
    alert("You were driving at " + top_speed + "km/h thats a normal speed");

} else if (top_speed >= 80 && top_speed < 120) {
    alert("You were driving at " + top_speed + "km/h thats a moderate 
    speed");

} else if (top_speed >= 120) {
    alert("You were driving at " + top_speed + "km/h that is a very high 
    speed");

} else {
    alert("You need to go faster " + top_speed + "km/h is too slow ");
}

Upvotes: 3

Related Questions