conversation function java script 
by useing this function we can convert variable data type into another data type
parse int
this function is converts a variables values in to the integer data types it convert each and every character of a string in integer until the possible conversions and returns the converted values
<script>
x=10;
y=20;
alert(parsInt((x)+y))
</script>
<script>
a="1a00"
alert (is nan(a));
</script>
by useing this function we can convert variable data type into another data type
parse int
this function is converts a variables values in to the integer data types it convert each and every character of a string in integer until the possible conversions and returns the converted values
<script>
x=10;
y=20;
alert(parsInt((x)+y))
</script>
parse float :-
a 
 it is same as pars int  to convert the input values as floating point  number  to check the Boolean values true  if it is  a  not a number  otherwise it return false , first it will convert the input string as number if it is converted successfully  then return false otherwise it return true<script>
a="1a00"
alert (is nan(a));
</script>