Question

我试图提示用户，直到输入等于数组中的一个元素？

do {
      var bestCities = ["miami","sanfrancisco","austin","chicago","phoenix"]
      var userInput = prompt('Whats your city?');
    } while (
        userInput !== bestCities[i]
      );
    alert('I love ' + i + ' also' );

Answer 1

可能是：

var bestCities = ["miami","sanfrancisco","austin","chicago","phoenix"];
var userInput;

do{
  userInput = prompt('Whats your city?') 
} while (bestCities.indexOf(userInput) === -1);

alert('I love ' + userInput + ' also' )

indexOf() 从数组中返回位置。

如果未找到匹配项，则

indexOf会返回-1。因此，当循环找到除-1之外的索引时，循环结束。例如，miami位于0位置，chicago位于3位置。

Answer 2

这是一个更好的架构：

var validCity = false;

while(!validCity) {
    var input = prompt("What is your city");
    if(bestCities.indexOf(input) != -1) validCity = true;
}

Answer 3

do {
      var bestCities = ["miami","sanfrancisco","austin","chicago","phoenix"]
      var userInput = prompt('Whats your city?');
    } 
while (bestCities.indexOf(userInput)==-1);
alert('I love ' + userInput  + ' also' );

只需检查数组索引就可以了解

如何提示直到满足条件？

3 个答案: