JavaScript 尝试并捕获

Question

无论我做什么，我的代码都不会报告任何错误。这是针对索引数组的，当我提示用户输入他们想要删除的列表编号时，我收到错误。如果它不在索引中或不是整数，它应该给我一个错误。

function deleteTask(){
    'use strict';
    //Prompt user
    var input = prompt("what task do you want to delete?");

    var delMessage = ' ';

    try {
        //Convert to integer
        var delTask = parseInt(input);
        //Validates that user input was number and is range of to do list
        if ((typeof delTask == 'number') && (delTask <= tasks.length)){
            if (delTask > 1){
                //removes element from array
                var oneDown = parseInt(delTask - 1);
                tasks.splice(oneDown, 1);
            }else{
                tasks.splice(0,1);
            } 

            delMessage = '<h2>To-Do</h2><ol>';
            for (var i = 0, count = tasks.length; i < count; i++) {
                delMessage += '<li>' + tasks[i] + '</li>';
            }
            delMessage += '</ol>';
            output.innerHTML = delMessage; 
        }
        //Return false to prevent submission:
        return false;

    }catch(ex){
        console.log(ex.message);
    }



}

Answer 1

简单，将以下代码添加到 try block 的开头if((input -parseInt(input ))!=0) throw new Error('非整数');

它应该可以解决问题。