How to add an arrow links in d3.js?

1

<svg width="500" height="500"></svg>

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47

// Create sample data
const nodes = [
  { id: 1, name: "Node 1" },
  { id: 2, name: "Node 2" },
  { id: 3, name: "Node 3" }
];

const links = [
  { source: 1, target: 2 },
  { source: 2, target: 3 }
];

// Create SVG element
const svg = d3.select("svg");

// Create arrowhead marker
svg.append("defs").append("marker")
  .attr("id", "arrow")
  .attr("viewBox", "0 -5 10 10")
  .attr("refX", 15)
  .attr("markerWidth", 6)
  .attr("markerHeight", 6)
  .attr("orient", "auto")
  .append("path")
  .attr("d", "M0,-5L10,0L0,5");

// Create links
svg.selectAll("line")
  .data(links)
  .enter()
  .append("line")
  .attr("x1", d => nodes[d.source - 1].id * 100)
  .attr("y1", 250)
  .attr("x2", d => nodes[d.target - 1].id * 100)
  .attr("y2", 250)
  .attr("stroke", "black")
  .attr("marker-end", "url(#arrow)");

// Create nodes
svg.selectAll("circle")
  .data(nodes)
  .enter()
  .append("circle")
  .attr("cx", d => d.id * 100)
  .attr("cy", 250)
  .attr("r", 10)
  .attr("fill", "blue");