Javascript boolean.toString()用法及代码示例

boolean.toString()是javascript中的内置函数，用于根据指定的布尔对象的值返回“true”或“false”字符串。
用法:

boolean.toString()

参数：此函数不接受任何单个参数。
返回值：它根据指定的布尔对象的值返回“true”或“false”字符串。

让我们看一下此boolean.toString()函数上的一些JavaScript代码：

• 示例1:

  <script> 
  // Here Boolean object obj is  
  // created for the value true. 
  var obj = new Boolean(true); 
    
  // Here boolean.toString() function 
  // is used for the created object obj. 
  document.write(obj.toString()); 
  </script>

  输出：

  true

• 示例2:

  <script> 
  // Here Boolean object obj is  
  // created for the value 1. 
  var obj = new Boolean(1); 
    
  // Here boolean.toString() function is 
  // used for the created object obj. 
  document.write(obj.toString()); 
  </script>

  输出：

  true

• 示例3:

  <script> 
  // Here Boolean object obj is 
  // created for the value -1. 
  var obj = new Boolean(-1); 
    
  // Here boolean.toString() function is 
  // used for the created object obj. 
  document.write(obj.toString()); 
  </script>

  输出：

  true

• 示例4:

  <script> 
  // Here Boolean object obj is 
  // created for the value 1.2 
  var obj = new Boolean(1.2); 
    
  // Here boolean.toString() function is 
  // used for the created object obj. 
  document.write(obj.toString()); 
  </script>

  输出：

  true

• 示例5:

  <script> 
  // Here Boolean object obj is created  
  // for the value as string "gfg" 
  var obj = new Boolean("gfg"); 
    
  // Here boolean.toString() function is  
  // used for the created object obj. 
  document.write(obj.toString()); 
  </script>

  输出：

  true

• 示例6:

  <script> 
  // Here Boolean object obj is created 
  // for the value false. 
  var obj = new Boolean(false); 
    
  // Here boolean.toString() function is 
  // used for the created object obj. 
  document.write(obj.toString()); 
  </script>

  输出：

  false

错误和异常：

• 示例1:这里的值geeksforgeeks会给出错误，因为不仅未定义该值，而且还预定义了false。

  <script> 
  // Here Boolean object obj is created  
  // for the value geeksforgeeks. 
  var obj = new Boolean(geeksforgeeks); 
    
  // Here boolean.toString() function is 
  // used for the created object obj. 
  console.log(obj.toString()); 
  </script>

  输出：

  Error: geeksforgeeks is not defined

• 示例2:在这里，不能将复数作为参数，而只能将整数值和字符串作为参数，这就是它返回错误的原因。

  <script> 
  // Here Boolean object obj is created for the 
  // value such as complex number 1+2i 
  var obj = new Boolean(1 + 2i); 
    
  // Here boolean.toString() function is  
  // used for the created object obj. 
  console.log(obj.toString()); 
  </script>

  输出：

  Error: Invalid or unexpected token

应用：

• 此函数的应用程序将根据给定对象的值返回“true”或“false”字符串。
  让我们看看此应用程序上的JavaScript程序：
  例：

  <script> 
  // Here Boolean object obj  
  // is created for the value 27 
  var obj = new Boolean(27); 
    
  // Here boolean.toString() function is  
  // used for the created object obj. 
  document.write(obj.toString()); 
  </script>

  输出：

  true