问题描述
let input;
const todos = [];
while (input !== 'exit') {
input = prompt('Type what you want to do');
if (input === 'new') {
input = prompt("What's your todo?");
todos.push(input);
} else if (input === 'list') {
console.log(`This is your list of todos: ${todos}`);
} else if (input === 'delete') {
input = prompt('Which todo would you like to delete?');
if (todos.indexOf(input) !== -1) {
todos.splice(1,1,input);
console.log(`You've deleted ${input}`);
}
} else {
break;
}
}
这就是我迄今为止尝试过的。 我正在开始编程,这是一个小练习的一部分,我必须根据提示要求添加一个新的待办事项,将其全部列出,然后删除。 我想要做的是:获取存储在输入变量中的输入,然后检查它是否在数组内部,如果它是肯定的,我想删除它而不是从索引而是从单词中删除。
喜欢:
如果这是一个愚蠢的问题,我深表歉意。我在网上试过了,没找到。
谢谢!
解决方法
您可以将循环更改为 do while
循环来检查出口,而不是最后使用 break
进行检查。
然后需要将indexOf
的结果存储起来,将item与索引拼接起来。
let input;
const todos = [];
do {
input = prompt('Type what you want to do');
if (input === 'new') {
input = prompt("What's your todo?");
todos.push(input);
} else if (input === 'list') {
console.log(`This is your list of todos: ${todos}`);
} else if (input === 'delete') {
input = prompt('Which todo would you like to delete?');
const index = todos.indexOf(input)
if (index !== -1) {
todos.splice(index,1);
console.log(`You've deleted ${input}`);
}
}
} while (input !== 'exit');
稍微更好的方法是采用 switch
statement。
let input;
const todos = [];
do {
input = prompt('Type what you want to do');
switch (input) {
case 'new':
input = prompt("What's your todo?");
todos.push(input);
break;
case 'list':
console.log(`This is your list of todos: ${todos}`);
break;
case 'delete':
input = prompt('Which todo would you like to delete?');
const index = todos.indexOf(input)
if (index !== -1) {
todos.splice(index,1);
console.log(`You've deleted ${input}`);
}
}
} while (input !== 'exit');
您的代码已修复如下:
input = prompt('Which todo would you like to delete?');
const index = todos.indexOf(input);
if (~index) {
todos.splice(index,1);
console.log(`You've deleted ${input}`);
}
您可以在相应的 MDN 文档中阅读有关 Array.prototype.splice()
和 bitwise operator 的更多信息。
按照 this 正确使用 splice。
你想要的是这样的:
todos.splice(yourIndex,1);
第一个参数是您想要操作数组的起始索引,第二个参数是计数。拼接到位,会修改数组。
,使用 indexOf 方法找到索引,然后使用 splice 方法!
let todos = ['one','two','three'];
let index;
// Wrap the whole code in function to make it resusable
let user_input = prompt(" Enter your to-do to delete ");
index = todos.indexOf(user_input);
if (index !== -1) {
todos = todos.splice(index,1);
console.log("Entered to-do deleted successfully");
} else {
alert("Entered to-do doesn't exists");
}
还请记住,作为初学者,有问题是件好事!