Question

我有一个使用onClick生成随机引号的脚本。但是，我需要的是将特定报价作为默认值打开。之后，onClicks应该产生随机结果。这是我到目前为止所得到的：

<button onClick="quotes()">ASK then CLICK</button>
<br>
<textarea id="txtbox" style="width:170px;  readonly></textarea>
<br>
<br>
<script>
    function quotes() {

        var aquote = new Array;
        aquote[0] = " This SHOULD ALWAYS APPEAR FIRST ";
        aquote[1] = "Think twice about this ";
        aquote[2] = "Save your money.... ";
        aquote[3] = "Real Estate is good ";
        aquote[4] = "Visit the Islands "

        rdmQuote = Math.floor(Math.random() * aquote.length);
        document.getElementById("txtbox ").value = aquote[rdmQuote];
    }
    window.onload = quotes;
</script>

Answer 1

您可以像这样重新组织代码，并为随机引用或固定引用创建专用函数：

<button onClick="randomQuote()">ASK then CLICK</button>
...
<script>
var quotes = [
    " This SHOULD ALWAYS APPEAR FIRST ",
    "Think twice about this ", 
    "Save your money.... ", 
    "Real Estate is good ";
    "Visit the Islands "
];

function randomQuote()
{
    showQuote(Math.floor(Math.random() * quotes.length));
}

function showQuote(index) {
    document.getElementById("txtbox ").value = quotes[index];
}

window.onload = function() {
    showQuote(0);
};
</script>

Answer 2

你唯一的问题是语法错误。您在getElementById("txtbox ")中有一个额外的空格，并且textarea的样式声明中缺少引号，否则代码可以使用：

document.getElementById("txtbox").value = aquote[rdmQuote];

http://jsfiddle.net/CkaMW/

Answer 3

您可以在HTML中显示默认文本，然后使用随机引号更改textarea的值。

<强> HTML

<textarea id="txtbox">This SHOULD ALWAYS APPEAR FIRST</textarea>

<强> JS

var aquote = [
    "Think twice about this ",
    "Save your money.... ",
    "Real Estate is good ",
    "Visit the Islands "
];

var random = -1;

function quotes() {
    var temp = random;
    // Make sure we do not display the same quote twice in a row
    while(temp == random) temp = Math.floor(Math.random() * aquote.length);
    random = temp;
    document.getElementById("txtbox").innerHTML = aquote[random];
}

如何使数组中的第一个var成为默认值

3 个答案:

JS Fiddle Demo