Question

我想创建一个脚本，从列表（数组）中询问您想要的项目，检查项目是否有库存，如果您的类型“列表”显示库存并退出程序（while循环）如果你输入“退出”

while (true) { // endless loop
  var search = prompt('Type the item you are looking for, type "list" to display the inventory, type "quit" to exit te store.');
  search = search.toLowerCase;
}
if (search = 'quit') {
  break; // if the client types quit, they exit the store, loop ends
} else if search == 'list'{
  write('<p>We currently have ' + inventory.join(', ') + ' in stock.</p>');
} else if (inventory.indexOf(search) > - 1) {
  write('<p>Yes, we have ' + search + ' in our stock.</p>');
} else {
  write('<p>Sorry, we don\'t have ' + search + ' in our stock</p>');
}

break语句不在循环中，但我真的不知道它应该去哪里......

有什么想法吗？

Answer 1

只要把整个＆＃34; if＆＃34;在＆＃34;内部构建＆＃34;而＃34;循环！

即，移动＆＃34;}＆＃34;从第4行到代码的结尾。

＆＃34;休息＆＃34;然后将与＆＃34; while＆＃34;构造

Answer 2

您的代码中至少有三个错误：

首先，if在Loop之外。第二个你错过括号arround一个如果声明。第一个if语句中的第三个你错过了第二个等号

＆＃13;

var search='1';
while (true) { // endless loop
  var search = prompt('Type the item you are looking for, type "list" to display the inventory, type "quit" to exit te store.');
  search = search.toLowerCase;

if (search == 'quit') {
  break; // if the client types quit, they exit the store, loop ends
} else if (search == 'list'){
  write('<p>We currently have ' + inventory.join(', ') + ' in stock.</p>');
} else if (inventory.indexOf(search) > - 1) {
  write('<p>Yes, we have ' + search + ' in our stock.</p>');
} else {
  write('<p>Sorry, we don\'t have ' + search + ' in our stock</p>');
}
}

＆＃13;

Answer 3

试试这个。您错放了括号，并在if语句中错过了==;

＆＃13;

while (true) { // endless loop
  var search = prompt('Type the item you are looking for, type "list" to display the inventory, type "quit" to exit te store.');
  search = search.toLowerCase;

if (search == 'quit') {
  break; // if the client types quit, they exit the store, loop ends
} else if search == 'list'{
  write('<p>We currently have ' + inventory.join(', ') + ' in stock.</p>');
} else if (inventory.indexOf(search) > - 1) {
  write('<p>Yes, we have ' + search + ' in our stock.</p>');
} else {
  write('<p>Sorry, we don\'t have ' + search + ' in our stock</p>');
}
}

＆＃13;

Answer 4

如果需要，您应该在while循环中检查数据并将其分解。

我还纠正了错误并测试了脚本。

您可以在我的评论中找到有关错误的详细信息。

while (true) { // endless loop
  var search = prompt('Type the item you are looking for, type "list" to display the inventory, type "quit" to exit te store.');
  search = search.toLowerCase();
      // After getting user input you want to check it and decide accordingly if
  // you want to stop the loop or you want to ask the user for input again
  if (search == 'quit') { // *** ERROR *** In your code you used a
// single = and that doesn't work for comparison in Javascript
    break; // if the client types quit, they exit the store, loop ends
  } else if (search == 'list') {// *** ERROR *** If you have more than a single if you need to always use parenthesis
    console.log('<p>We currently have ' + inventory.join(', ') + ' in stock.</p>');
  } else if (inventory.indexOf(search) > -1) {
    console.log('<p>Yes, we have ' + search + ' in our stock.</p>');
  } else {
    console.log('<p>Sorry, we don\'t have ' + search + ' in our stock</p>');
  }

}

Answer 5

您的代码中存在多个错误，一些语法错误，例如缺少括号，或仅使用一个等号。 break关键字需要在循环内部，否则就没有循环可以突破。

但是，如果我们说if(!search) continue;而不是我们说if(!search) break;的那部分，你可以通过点击取消或输入一个空字符串来摆脱循环，如果你问我这更有意义。

var inventory = ['tea','sugar'];
while (true) { // endless loop
  var search = prompt('Type the item you are looking for, type "list" to display the inventory, type "quit" to exit te store.');

  if(!search) continue;

  search = search.toLowerCase();

  if (search == 'quit') {
    break; // if the client types quit, they exit the store, loop ends
  } else if (search == 'list') {
    alert('<p>We currently have ' + inventory.join(', ') + ' in stock.</p>');
  } else if (inventory.indexOf(search) > -1) {
    alert('<p>Yes, we have ' + search + ' in our stock.</p>');
  } else {
    alert('<p>Sorry, we don\'t have ' + search + ' in our stock</p>');
  }
}

break语句在while循环中放错位置

5 个答案: