JavaScript 代码不断重复语句。我怎样才能阻止这个？

Question

我正在创建一个 12 天的圣诞节 javascript 程序，当我打印出该语句时，它不断重复该语句。你能给我一些关于如何解决这个问题并让程序正常工作的建议吗？

var day = ["first", "second", "third", "fourth", "fifth", "sixth", 
"seventh", "eighth", "ninth", "tenth", "eleventh", "twelfth"];
var song = "";

for (var x = 0; x <= 13; x++) {
song += "On the " + day[x] + " day of Christmas";
song += " my true love gave to me: ";

if (x == 0) {
    song += "a partridge in a pear tree."
} 
else {
    switch (x) {
        case 12:
            song += ("twelve drummers drumming, ");
        case 11:
            song += ("eleven pipers piping, ");
        case 10:
            song += ("ten lords a-leping, ");
        case 9:
            song += ("nine ladies dancing, ");
        case 8:
            song += ("eight maids a-milking, ");
        case 7:
            song += ("seven swans a-swimming, ");
        case 6:
            song += ("six geese a-laying, ");
        case 5:
            song += ("five gold rings,");
        case 4:
            song += ("four calling birds, ");
        case 3:
            song += ("three french hens, ");
        case 2:
            song += ("two turtle doves ");
        case 1:
            song += ("and a partridge in a pear tree.");
            break;
    }
}
console.log(song);}

Answer 1

switch case 中缺少 break 语句。

switch (x) {
        case 12:
            song += ("twelve drummers drumming, ");
            break;
        case 11:
            song += ("eleven pipers piping, ");
            break;
        case 10:
            song += ("ten lords a-leping, ");
            break;
        case 9:
            song += ("nine ladies dancing, ");
            break;
        case 8:
            song += ("eight maids a-milking, ");
            break;
        case 7:
            song += ("seven swans a-swimming, ");
            break;
        case 6:
            song += ("six geese a-laying, ");
            break;
        case 5:
            song += ("five gold rings,");
            break;
        case 4:
            song += ("four calling birds, ");
            break;
        case 3:
            song += ("three french hens, ");
            break;
        case 2:
            song += ("two turtle doves ");
            break;
        case 1:
            song += ("and a partridge in a pear tree.");
            break;
    }