Typescript中的TypeError [英] TypeError in Typescript

问题描述

这是我的问题:我收到此错误:

Here my problem: I get this error:

未捕获的TypeError:对象原型只能是Object或为null:未定义

Uncaught TypeError: Object prototype may only be an Object or null: undefined

export abstract class AbstractLogicExpression {
    protected _logicChildExpressions: AbstractLogicExpression[] = Array();
    protected _precedence = 0;
    protected _parsed = false;
    protected _expressionType = "";

    protected rightAssociative = false;

    public toDNF() {
        for (let i = 0; i < this.logicChildExpressions.length; i++) {
            let actualLogicExpression: AbstractLogicExpression = this.logicChildExpressions[i];

            if (actualLogicExpression._expressionType == "~") {

                let logicConjunction = actualLogicExpression.logicChildExpressions[0];

                let var1 = logicConjunction.logicChildExpressions[0];
                let var2 = logicConjunction.logicChildExpressions[1];

                if (logicConjunction._expressionType == "*") {
                    actualLogicExpression.logicChildExpressions[0] = new LogicOr();
                    //actualLogicExpression.logicChildExpressions[0].add(new LogicNeg(var1));
                    //actualLogicExpression.logicChildExpressions[0].add(new LogicNeg(var2));
                }
            }
        }
    }
}

由于出现两条注释行之前的行，导致出现此错误:

I get this error because of the line before the two commented lines:

actualLogicExpression.logicChildExpressions[0] = new LogicOr();

我通过注释并取消注释行来对其进行测试，因为错误消息中没有行号.

I tested it by comment and uncomment the lines, because I get no line number in the error message.

有人知道我能做什么吗?如果您需要更多代码.我可以发布一些东西...

Does someone know what I can do? If you need a little more code. I can post something...

以下是LogicOr的代码: https://pastebin.com/T28Zjbtb

Here the code of LogicOr: https://pastebin.com/T28Zjbtb

推荐答案

在此行出现错误:

actualLogicExpression.logicChildExpressions [0] =新的LogicOr();

actualLogicExpression.logicChildExpressions[0] = new LogicOr();

错误消息是

未捕获的TypeError:对象原型只能是一个对象或为null:未定义

Uncaught TypeError: Object prototype may only be an Object or null: undefined

一旦您熟悉了类及其工作方式，就很容易理解( https://basarat.gitbooks.io/typescript/docs/classes.html ).

It is very easy to understand once you are familiar with Classes and how they work (https://basarat.gitbooks.io/typescript/docs/classes.html).

该错误表示 new LogicOr 失败，因为 LogicOr 正在扩展 undefined .简单示例:

The error means that new LogicOr is failing because LogicOr is extending something that is undefined. Simple example:

let Bar; 
class Foo extends Bar { } // Uncaught TypeError: Object prototype may only be an Object or null: undefined

更多

修复 LogicOr 中的错误及其继承链.

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