Change current Element using d3

I want to change width and style of a rect element when it gets hover.

I tried this But didn’t work

   .on('mouseover', (d, i) => {
   'width', w + 10).style('stroke', 'black');
             // and this too
              this.attr('width',  w+ 10).style('stroke', 'black');

I’m using d3 v5

Use function instead.

function ( d, i ) {

Thanks it works
Can you tell me why it is working?

This happens because the arrow functions don’t bind their own this (or the arguments array!) unlike “normal” functions do. It’s a little tricky concept to catch at first, but you might read and do your tests to make the concept clear. I remember seen one of the books by Kyle Simpson (You Don’t Know Js) talking about that and also Eloquent JS explained it.

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