Add A Legend To D3 Force Directed Graph

So I am trying to create a legend in the bottom right corner of my D3. I have written all of the code for the legend but it comes up as just a black screen with the force-directed

Solution 1:

This is incorrect:

var legend = d3.append('svg').append("g")

should have been (you should append, the g group which holds legend to the svg)

var legend = svg.append("g")