CODEWITHSUNDEEP
javascriptselect
yasser Eltibili
yasser Eltibili

Reputation: 134

Using pure JavaScript trying to change the default option of select box, but having an uncaught TypeError: Cannot read property '0' of undefined

Using vanilla JavaScript I am trying to change the default option of a select box.

var temp = "Approve";
var mySelect = document.querySelector('[id^="select_leave_action_"]').id;

for(var i, j = 0; i = mySelect.options[j]; j++) {
    if(i.value == temp) {
        mySelect.selectedIndex = j;
        break;
    }
}

When I execute the above code I get the following error:

Uncaught TypeError: Cannot read property '0' of undefined at :4:39`

What is wrong with my code?

I tried to use getElementsByClassName instead of querySelector, but still have the same problem.

Upvotes: 0

Views: 138

Answers (1)

CherryDT
CherryDT

Reputation: 29072

Remove .id.

The ID is a string and won't have an options property. You want to store the select element itself (not its ID) to access its options.

(Also it's even simpler to just set mySelect.value = temp, the only difference to your current method will be how the case is handled where temp is not existing in the options that exist. Depending on the browser, setting the value directly may display the box empty if no fitting option exists.)

Upvotes: 1

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