[Solved]-D3.JS how to load 3 csv files and change data on line chart with button click event?-d3.js

bind renderdata to the buttons at runtime. if you use d3 v6:

d3.selectall('.buttons > .but').on('click', (e, i) => renderdata(i));

for v5 and earlier:

d3.selectall('.buttons > .but').on('click', (i) => renderdata(i));