Guys can someone pls explain me whats wrong with this code?

Question

The code:

var e=document.getElementsByClassName('uline');
for (var i=0;i<=e.length;i++){
e[i].style.backgroundColor="white";
}

var lin=document.getElementsByTagName('a');
for(var a=0;a<=lin.length;a++){
lin[a].style.color='rgb(55, 106, 247)';
lin[a].style.borderColor='white';

}

When running the code it stops from the first loop above ,but the first loop works and the second doesn't.

In the chrome developer tool it says

Uncaught TypeError: Cannot read properties of undefined (reading 'style')

Can someone explain what had gone wrong?

Answer 1

// Try it

for (let i=0; i<e.length-1; i++){
...
}

Answer 2

If you are sure there are elements within the document having "uline" class, and also the hyperlinks; then your problem was with the loop condition. You should set the loop to run while the counter variable was less than the array length, not while the counter was less than or equal to the array length

This is because indices are zero-based positive values, from 0 up to (length of array - 1, inclusively ). So if you have a 20 elements array, valid indices begins with 0 (zero), and ends with (20 - 1 ~ 19)

(Edited)

Answer 3

yes it worked .thank you @soloprog.
And also can I know why its worked, if you don't mind.

Answer 4

K.A.D.H.M

he answered it :)

Answer 5

@Ipang

Thanks for your explanation.