D3.js selection.append() Function

The selection.append() function is used to append a new element to the HTML tag name as given in the parameters to the end of the element. If the type that is given is a function then it must be evaluated for each element that is in the selection.
Syntax:
selection.append(type);
Parameters: This function takes only one parameter which is given above and described below.
- type: This parameter takes a string that defines the type of the element.
Return Value: This function must return an element to be appended at the end.
Example 1: In the following example, elements are appended to each selected element.
HTML
| <!DOCTYPE html> <htmllang="en">  <head>     <metacharset="UTF-8">     <metaname="viewport"path1tent="width=device-width,              initial-scale=1.0">     </script>      <style>         h1 {             color: green;         }          p {             background-color: #f2f2f2;             padding: 10px;             width: 300px;             line-height: 5px;         }          p:hover {             background-color: grey;             padding: 10px;             cursor: pointer;         }          div {             width: 50px;             height: 50px;             background-color: green;             margin: 10px;         }     </style> </head>  <body>     <h1>zambiatek</h1>     <h4>D3.js | selection.append() Function</h4>      <p><b>Click me</b></p>     <p><b>Click me</b></p>      <script>         function func() {             // Selecting all p and             // Appending a DIV to each p tag             var chk = d3.selectAll("p")                 .append("div");             var div = document.querySelector("div");             console.log(div)         }         let btn = document.querySelector("p");         btn.addEventListener("click", func);     </script> </body>  </html>  | 
Output:
- 
Before clicking the “click me” element: 
- 
After clicking the “click me” element: 
Example 2: In the following example elements are appended only to the first element.
HTML
| <!DOCTYPE html>  <htmllang="en">  <head>      <metacharset="UTF-8">      <metaname="viewport"            path1tent="width=device-width,                      initial-scale=1.0">    </head>  <style>     h1{         line-height: 5px;         color: green;     }     h1, h2, p, h4, h5, h6{         background-color: #f2f2f2;         padding:20px;         width: 300px;         line-height: 5px;     }     p:hover{         background-color: grey;         cursor: pointer;     }     div{         width: 50px;         height: 50px;         background-color: green;         margin:10px;     } </style>  <body>       <h1>Geeks for zambiatek</h1>     <p>Click me.</p>     <p>Click me.</p>   <scriptsrc=    </script>   <script>    function func(){             // Selecting  p and             // Appending a DIV to the p tag             // Only first p tag is effected             var chk = d3.select("p")                         .append("b");             var b=document.querySelector("b");             b.innerText=" This <b> tag is appended."         }     let btn=document.querySelector("p");     btn.addEventListener("click", func);    </script>  </body>  </html> | 
Output:
- 
Before clicking the “click me” button: 
- 
After clicking the “click me” button: 
 
				 
					



