javascript regex validate years in range

For a range from 1950 to 2050 you may use the following regex:

^19[5-9]\d|20[0-4]\d|2050$

Online demo

RegExp does not seem to be the right tool here. If you have the year values already isolated surely a simple comparison would work :

if (+yr >= 1990 && +yr <= 2010)

The +yr converts the string to a number

Try this:

1990 - 2010:

/^(199\d|200\d|2010)$/

1950 - 2050:

/^(19[5-9]\d|20[0-4]\d|2050)$/

Other examples:

1945 - 2013:

/^(194[5-9]|19[5-9]\d|200\d|201[0-3])$/

1812 - 3048:

/^(181[2-9]|18[2-9]\d|19\d\d|2\d{3}|30[0-3]\d|304[0-8])$/

Basically, you need to split your range into easy "regexable" chunks:

1812-3048: 1812-1819 + 1820-1899 + 1900-1999 + 2000-2999 + 3000-3039 + 3040-3048
    regex: 181[2-9]    18[2-9]\d   19\d\d      2\d{3}      30[0-3]\d   304[0-8]

Regex:

/^(19[5-9]\d|20[0-4]\d|2050)$/

Easier...

var year = parseInt(textField.value, 10);
if( year >= 1950 && year <= 2050 ) {
    ...
}