JavaScript - toConstantCase()

gistfile1.js

function toConstantCase() {
	var a = arguments;
	if( a.length == 1 ) {
		return a[0].replace( toConstantCase.REGEX, toConstantCase ).toUpperCase();
	}
	return a[0][0] + "_" + a[0][1] + ( a[0][2] ? a[0][2] : "" );
}
toConstantCase.REGEX = /[a-z][A-Z]|[A-Z]{2}[a-z]/g;

//
// EXAMPLE
//
console.log( toConstantCase( "someValue" )            ); // SOME_VALUE
console.log( toConstantCase( "someSuperValue" )       ); // SOME_SUPER_VALUE
console.log( toConstantCase( "someSuperDOOPERValue" ) ); // SOME_SUPER_DOOPER_VALUE