JavaScript ReferenceError – 对未定义属性“x”的引用

如果脚本尝试访问不存在的对象属性，则会出现此 JavaScript 警告引用未定义属性。

信息：

ReferenceError: reference to undefined property "x" (Firefox)

错误类型：

ReferenceError(Only reported by firefox browser)

错误原因：脚本试图访问不存在的对象属性。

示例1：在本示例中，访问了有效的属性，因此没有发生错误。

HTML

    
        
        
    
    
        
            GeeksforGeeks
        
          

            JavaScript ReferenceError 
            Reference to undefined property
        
  
        
            click here
        
        
  
        
            var el_down = document.getElementById("GFG_DOWN");
            function GFG() {
                "use strict";
                var AR_GFG = { prop_1: "Val_1" };
                return AR_GFG.prop_1;
            }
            function Geeks() {
                try {
                    GFG();
                    el_down.innerHTML =
                      "'Reference to undefined property'"+
                      " error has not occurred";
                } catch (e) {
                    el_down.innerHTML = 
                      "'Reference to undefined property'"+
                      "error has occurred";
                }
            }
        
    

输出：

例2：在这个例子中，访问了未定义的属性，所以发生了错误。

HTML

    
        
        
    
    
        
            GeeksforGeeks
        
          

            JavaScript ReferenceError 
            Reference to undefined property
        
  
        
            click here
        
        
  
        
            var el_down = document.getElementById("GFG_DOWN");
            function GFG() {
                "use strict";
                var GFG = {};
                return GFG.prop1;
            }
            function Geeks() {
                try {
                    GFG();
                    el_down.innerHTML = 
                      "'Reference to undefined property'"+
                      "error has not occurred";
                } catch (e) {
                    el_down.innerHTML = 
                      "'Reference to undefined property'"+
                      "error has occurred";
                }
            }
        
    

输出：