[javascript] try/catch

References: w3schools

Source

function myFunction() {

var message, x;

message = document.getElementById("p01");

message.innerHTML = "";

x = document.getElementById("demo").value;

try {

if(x == "") throw "empty"; 

if(isNaN(x)) throw "not a number"; 

x = Number(x); 

if(x < 5) throw "too low"; 

if(x > 10) throw "too high"; 

} 

catch(err) {

message.innerHTML = "Input is " + err; 

} 

}