In my simple bookmarklet, I call all input
elements of the document, and then try to try to access selectionStart
of each element:
javascript: (function () {
var inps=document.getElementsByTagName('input');
for (var i = 0; i < inps.length; i++) {
var el = inps[i];
if ('selectionStart' in el) {
console.log("o: " + (typeof el));
console.log("x: " + (typeof el.nonexistent));
console.log("s: " + (typeof el.selectionStart));
}
}
})();
this code gives the following lines in the console:
"o: object" - as expected,
"x: undefined" - as expected,
but for el.selectionStart
no output is given and "NS_ERROR_FAILURE" is shown in the console. Can anybody explain why does this happen? (additional general question - where can I find the meaning or any details about such errors thrown by Firefox?)
You can not access selectionStart
of a type hidden
element, or even type button
: http://jsfiddle.net/DerekL/pbCnQ/