Question

＆＃13;

var areYouReady = prompt("What do you want to do?").toLowerCase();
var starting_DescriptionStart;
var starting_DescriptorOfThing;
var starting_Thing;
var starting_DescriptionEnd;

if(areYouReady === "generate"){
//Just runs the generator
	
	 starting_DescriptionStart = ["You see a"];
			
	 starting_DescriptorOfThing = ["Large", "Small", "Red", "Blue", "Green", "Black", "White", "Invisible", "Camo", "Striped", "Breathing", "Living", "Sentient"];
			
	 starting_Thing = ["Chest", "Snake", "Spider", "Bird", "Bull", "Minotaur", "Sword", "Necklace", "Amulet", "Crown", "Pile of coins", "Deer", "Bunny", "Person", "Goblin", "Orc", "Wizard", "Board", "Ketchup"];

	 starting_DescriptionEnd = ["that wants to kill you.", "in a desert.", "on youtube.", "in a dark dungeon.", "in your neighbors house.", "underground.", "in a tree.", "in a restaurant.", ""];
			
			// Random numbers are made 
			var randomNumber1 = parseInt(Math.random() * starting_DescriptionStart.length);
			var randomNumber2 = parseInt(Math.random() * starting_DescriptorOfThing.length);
			var randomNumber3 = parseInt(Math.random() * starting_Thing.length);
			var randomNumber4 = parseInt(Math.random() * starting_DescriptionEnd.length);
			generatedArea = starting_DescriptionStart[randomNumber1] + " " + starting_DescriptorOfThing[randomNumber2] + " " + starting_Thing[randomNumber3] + " " + starting_DescriptionEnd[randomNumber4];	
		
		alert(generatedArea);
	
	
}else if(areYouReady === "add description start"){
	//Lets you add a descriptionStart
	var s_DescStart = starting_DescriptionStart.length + 1;
	
	var inputA = prompt("What do you want to add to the description start");
	
	starting_DescriptionStart[s_DescStart] = inputA;
	
	alert(starting_DescriptionStart[1]);
}

＆＃13;

我有这个代码，只需添加到数组就可以轻松添加，但是如果我想创建一个允许用户添加它的代码，然后运行它。

运行时出现此错误，输入＆＃34;添加说明开始＆＃34;

未捕获的TypeError：无法读取属性＆＃39;长度＆＃39;未定义的

但是，我不知道为什么它说它是一个全局变量时未定义。

Answer 1

在else if声明中，您没有以任何方式定义starting_DescriptionStart。它仍未定义，因此它没有长度。

starting_DescriptionStart在代码开头被声明为变量，仅在if语句中定义。

未捕获的TypeError：无法读取属性＆＃39; length＆＃39;未定义的，

1 个答案: