使用JS循環播放一系列歌曲。 如果歌曲在陣列中，請警告“是”。 如果不是，請警告“否”

Question

我正在嘗試顯示樂隊在新網站上播放的歌曲列表。 用戶輸入歌曲名稱（在名為“ liveSearchBox”的輸入標簽中），然后單擊“ findSong”按鈕。 如果我們播放歌曲，我想提醒“是的，我們播放！”。 如果我們不這樣做，我想提醒“對不起，我們不播放。” 我已經嘗試了好幾個小時才能找出解決方案，但是還不夠先進。 謝謝你的幫助！

這是我的HTML代碼：

<div class="live-search-list">

    <input type="text" id="liveSearchBox" placeholder=" Search Songs or Artist">
    <button id="findSong"> Click to Find!</button>
    <ul id="songList">
        <li class="song"> Margaritaville</li>
        <li class="song"> Boys of Summer</li>
        <li class="song"> Somebody Like You</li>
    </ul>

</div>

這是我的Javascript：

var songList = ["Margaritaville","Boys of Summer","Somebody Like You"];
var findButton = document.getElementById("findSong");
var songQuery = document.getElementById("liveSearchBox");
var songListItem = document.getElementsByClassName("song");

findButton.onclick = function(){
   for (var i = 0; i<songList.length; i++){
       if (songQuery.value === songList[i]){
           alert('Yes, we play "' +  songQuery.value + '"!');
       }  else {
             i++;
          }

  } 

};

Answer 1

使用indexOf ：

if (songList.indexOf(songQuery.value) != -1)
    alert('yes');
else
    alert('no');

Answer 2

使用indexOf是可以的，但是如果您想要一個在任何瀏覽器中都可以使用的解決方案，這是最快的方法：

function isInArray(array, item) {
    for (i = 0; i < array.length; i++)
        if (array[i] === item)
            return true;
    return false;
}

findButton.onclick = function() {
    if (isInArray(songList, songQuery.value))
        alert('Yes, we play "' + songQuery.value + '"!');
    else
        alert('Sorry, we don\'t play "' + songQuery.value + '".');
};

Answer 3

findButton.onclick = function(){
    var msg = !!~songList.indexOf(songQuery.value) ? 'Yes, we play "' +  songQuery.value + '"!' : 'No we do not play this song.';
    alert(msg);
}

也許這對您來說更容易理解：

findButton.onclick = function(){
    var msg = songList.includes(songQuery.value) ? 'Yes, we play "' +  songQuery.value + '"!' : 'No we do not play this song.';
    alert(msg);
}

或這個：

findButton.onclick = function(){
    if(songList.includes(songQuery.value)) {
        alert('Yes, we play "' +  songQuery.value + '"!');
    } else {
        alert('No we do not play this song.');
    }
}

Answer 4

 var songList = ["Margaritaville", "Boys of Summer", "Somebody Like You"], findButton = document.getElementById("findSong"), songQuery = document.getElementById("liveSearchBox"); findButton.onclick = function() { if (typeof songQuery.value === 'undefined' || songQuery.value === null || songQuery.value === '') { alert('please input the song name.'); return false; } if (songList.indexOf(songQuery.value) > -1) { alert('Yes, we play "' + songQuery.value + '"!'); } else { alert('Sorry "' + songQuery.value + '" was not found!'); } }; 

 <div class="live-search-list"> <input type="text" id="liveSearchBox" placeholder=" Search Songs or Artist"> <button id="findSong">Click to Find!</button> <ul id="songList"> <li class="song">Margaritaville</li> <li class="song">Boys of Summer</li> <li class="song">Somebody Like You</li> </ul> </div>