Question

所以我有一个if语句，我想要它，如果条件为真，则抛出一个错误。它是用户从名为myArr的数组中删除项目的表单，如果myArr中不存在该项，我希望它抛出错误。

$('#remove_user').submit(function(){
    id = $('#user_num').val();
    diffVal = $.grep(myArr, function(value, i){
        return value != id;
    });
    if (diffVal.length == myArr.length) {
        //I want the error here to say "Does not exist."
    } else {
        myArr = diffVal
    };
    $('#user_list').html('');
    for (var i=0; i < myArr.length; i += 1) {
        $('#user_list').append('<li>' +myArr[i]+ '</li>');
    };
    return false;
});

Answer 1

您可以使用

throw "Item does not exist!"

但是我发现最好抛出一个Error对象，如下所示：

throw new Error("Item does not exist!");

如果你抛出一个Error，你可以获得更好的可追溯性。令人遗憾的是，JavaScript中的错误处理仍然很糟糕。

Answer 2

只需使用 throw ：

if (diffVal.length == myArr.length) {
    //I want the error here to say "Does not exist."
    throw "Item does not exist in the array";
}

Answer 3

我个人最喜欢的是在投掷错误时也使用跟踪

if (diffVal.length == myArr.length) {
    //I want the error here to say "Does not exist."
    Console.log("Error: Does not exist");
    Console.trace();
    throw new Error("Item does not exist");
}

如何抛出异常？

3 个答案: