當前位置: 首頁>>編程示例 >>用法及示例精選 >>正文


d3.js d3.set.empty()用法及代碼示例

如果給定數組的元素為零,則D3.js中的set.empty()函數用於返回true,否則返回false。

用法:

d3.set([Array]).empty();

參數:此函數接受單個參數Array,無論該參數是否為空,都將對其進行搜索。


返回值:如果給定數組為空,則返回true,否則返回false。

以下程序說明了D3.js中的d3.set.empty()函數:

示例1:

<!DOCTYPE html> 
<html> 
  
<head> 
    <title> 
        d3.set.empty() function
    </title> 
      
    <script src = "https://d3js.org/d3.v4.min.js"></script> 
</head> 
  
<body> 
    <script> 
      
         // Initialising an array 
         Array1 = ["a"]; 
         Array2 = []; 
         Array3 = ["Geeks", "gfg", "GeeksforGeeks"]; 
            
         // Calling the d3.set.empty() function 
         A = d3.set(Array1).empty(); 
         B = d3.set(Array2).empty(); 
         C = d3.set(Array3).empty(); 
            
         // Getting the value true if the given array is  
         // empty otherwise returns false 
         console.log(A); 
         console.log(B); 
         console.log(C); 
    </script> 
</body> 
  
</html>                    

輸出:

false
true
false

示例2:

<!DOCTYPE html> 
<html> 
  
<head> 
    <title> 
        d3.set.empty() function
    </title> 
      
    <script src = "https://d3js.org/d3.v4.min.js"></script> 
</head> 
  
<body> 
    <script> 
      
        // Calling the d3.set.empty() function 
        // with a array as the parameter  
        A = d3.set([1, 2, 3, 3]).empty(); 
        B = d3.set([]).empty(); 
        C = d3.set(["a", "b", "c", "a", "b", "c"]).empty(); 
        
        // Getting the value true if the given array is 
        // empty otherwise returns false 
        console.log(A); 
        console.log(B); 
        console.log(C); 
    </script> 
</body> 
  
</html>                    

輸出:

false
true
false

參考: https://devdocs.io/d3~5/d3-collection#set_empty



相關用法


注:本文由純淨天空篩選整理自Kanchan_Ray大神的英文原創作品 D3.js | d3.set.empty() Function。非經特殊聲明,原始代碼版權歸原作者所有,本譯文未經允許或授權,請勿轉載或複製。