Ext isNumber

Some of the testings with Ext.isNumber are as follows..


Ext.isNumber(null)) false
Ext.isNumber(undefined) false
Ext.isNumber('') false
Ext.isNumber('1') false
(Ext.isNumber(1)) true
Ext.isNumber('1.234')false
(Ext.isNumber(1.234))true
(Ext.isNumber('1AS')false
(Ext.isNumber('AS1')false
Ext.isNumber('.1132')false
(Ext.isNumber(.132))true
Ext.isNumber('asdf')false
asdf is not defined [Break on this error] console.log("(Ext.isNumber(adsf))"+Ext.isNumber(asdf));

JavaScript isNumeric / Number validation

/* Takes input string and returns true if it is number else returns false */
function IsNumeric(sText){
/* Dont copy paste this code directly as it is containing logical errors */
/* Hint to find the bug in this code : If I pass number to this function it fails. */
var ValidChars = "0123456789.";
var IsNumber=true;
var Char;

for (i = 0; i < sText.length && IsNumber == true; i++)
{
Char = sText.charAt(i);
if (ValidChars.indexOf(Char) == -1)
{
IsNumber = false;
}
}
return IsNumber;

}


I used the above code to validate my input string .
Problem comes when we pass null or undefined strings. we need to add a validation for that.

But after adding that validation I thought it's perfect .But still there was one flaw
That is, If I pass a number to this function it fails because sText.length wont work on a number :(

The final code after doing some modifications to the above code is

function IsNumeric(sText){

if(sText == undefined || sText == null ) return false;

sText=''+sText //if input is not a string then we are making it to string.
//Otherwise sText.length wont work.
var ValidChars = "0123456789.";
var Char;


for (i = 0; i < sText.length ; i++)
{
Char = sText.charAt(i);
if (ValidChars.indexOf(Char) == -1)
{
return false;
}
}
return true;

}


To realize this I wasted good amount of time..So to save others time I am writing this blog..
Happy Coding and have fun :)

Ping may fail even if the system is in network

Generally we use PING IP command to test the connectivity of a system.
If it fails we think it's not reachable But it's not true always.
I faced the same situation today..
There is a system for which I can do ssh -p 2021 root@XXXXXX

But for the same box I can't ping.
Learning is ping uses icmp 'echo-request' . If it is blocked in that server we can't ping...