setting element oninput from javascript array variable

Asked Jun 13 '18 at 14:51

Active Jun 13 '18 at 14:51

Viewed 12 times

I have code akin to the following:

// Already existing: var my_elements - an array of elements.
for (var i = 0, len = my_elements.length; i < len; i++){
    my_elements[i].oninput = function(){blue_background(my_elements[i])};
}

function blue_background(my_element){
    my_element.style.backgroundColor = "blue";
}

The problem with this, however, as far as I can tell, as the array is looped through, by the time the event triggers, [i] is no longer an existing variable and I get an alert of "undefined".

asked Jun 13 '18 at 14:51

lilHar

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You have to show all the relevant code so we can reproduce your issue. Add the HTML and any CSS and show us when the code you've posted actually runs. – Scott Marcus Jun 13 '18 at 14:53
1

change var with let – Ruben Karapetyan Jun 13 '18 at 14:53
1

As for your specific issue. Change `var i` to `let i` so that you get block level scope – Scott Marcus Jun 13 '18 at 14:53
Please provide a [mcve]. You should have just enough code to illustrate the error you get without any extra unrelated code. Anyone should be able to run it themselves and get the same result. – Code-Apprentice Jun 13 '18 at 14:54

setting element oninput from javascript array variable

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