Reputation: 55
I need to make sure that the user inputs all numbers not letters in weight, height and age
function calculate(){
var w= document.getElementById("weight").value;
var h=document.getElementById("height").value;
var a=document.getElementById("age").value;
//if all numbers enter loop
var height= Number(h);
if(document.one.gender[0].checked)
{var ans= 50+ (height/2) ;}
else
{var ans=46+ (height/2) ;}
alert(ans);
}
// else alert("enter numbers only");
Upvotes: 1
Views: 48
Reputation: 6209
You can check the following way:
if (isNaN(document.getElementById("weight").value)){
// Not number
} else {
// It is number
}
Edited code:
function calculate(){
var w= document.getElementById("weight").value;
var h=document.getElementById("height").value;
var a=document.getElementById("age").value;
if (isNaN(w) || isNaN(h) || isNaN(a)) {
alert("Please ensure that weight, height and age are integers");
return;
}
//Your code if all numbers
}
Upvotes: 1