javascript - 我只想让这个函数提醒该书在遍历 bookStore 数组后一次没有找到，而不是在每个索引处。

Question

function checkStore(string) {
    for (var i = 0; i < BookStore.length; i++) {
        if (BookStore[i].title === string) {
            prompt('We found your book! ' + string + ', by ' + BookStore[i].author +
                '. It costs ' + BookStore[i].price +
                ' would you like to add it to your cart?');
        } else {
            alert('Sorry ' + string + ' was not found, try another title?');
        }
    }
}

这就是发生的情况，假设 BookStore.length = 6。如果 BookStore[i].title === string 在索引 4 处为 true，这就是我得到的

'Sorry ' + string + ' was not found, try another title?'
'Sorry ' + string + ' was not found, try another title?'
'Sorry ' + string + ' was not found, try another title?'
'Sorry ' + string + ' was not found, try another title?'
'We found your book! ' + string + ', by ' + BookStore[i].author +
                    '. It costs ' + BookStore[i].price +
                    ' would you like to add it to your cart?'
'Sorry ' + string + ' was not found, try another title?'

如何让它只打印 'Sorry ' + string + ' was not find, try another title?' 一次，如果不正确，并且

'We found your book! ' + string + ', by ' + BookStore[i].author +
                        '. It costs ' + BookStore[i].price +
                        ' would you like to add it to your cart?' 

它本身何时为真？

谢谢!

Answer 1

使用Array.prototype.some()的解决方案:

function checkStore(string) {
    var book;
    if (BookStore.some(function (b) {
        return b.title === string && (book = b);
    })) {
        prompt('We found your book! ' + string + ', by ' + book.author + '. It costs ' + book.price + ' would you like to add it to your cart?');
    } else {
        alert('Sorry ' + string + ' was not found, try another title?');
    }
}