[英]Display Random Item From Array On Button Click, NO TWO IN A ROW
我有一個按鈕,用於顯示引用和數組作者。 每次單擊該按鈕時,我需要該按鈕以顯示隨機報價/作者。 連續沒有兩個相同的引號/作者!
window.onload = function()
{
//assign var to quoteText id contents
var quoteSpan = document.getElementById("quoteText");
//assign var to authorText id contents
var authorSpan = document.getElementById("authorText");
//assign var to submitButton contents
var submitButton = document.getElementById('submit');
var quotes = [
{'text': '"Whatever you are, be a good one."', 'author': '-Abraham Lincoln'},
{'text': '"It has been my philosophy of life that difficulties vanish when faced boldly."', 'author': '-Isaac Asimov'},
{'text': '"Enjoy life. There’s plenty of time to be dead."', 'author': '-Anonymous'},
{'text': '"Every moment is a fresh beginning."', 'author': '-T.S. Eliot'},
{'text': '"One day your life will flash before your eyes. Make sure it is worth watching."', 'author': '-Anonymous'}
];
var oldQuoteIndex = -1; //unfound item in array is -1
//function determining random quote
function nextQuote() {
do {
var newQuoteIndex = Math.floor(Math.random() * quotes.length); //picks random quote index from quotes array
} while (newQuoteIndex == oldQuoteIndex); //while index of newly chosen quote is the same as the index of old quote
quoteSpan.innerHTML = quotes[newQuoteIndex].text; //make HTML's quoteText random quote
authorSpan.innerHTML = quotes[newQuoteIndex].author; //make HTML's authorText random author
var oldQuoteIndex = newQuoteIndex; //make old index same as new index, so that next time it runs, the WHILE aspect causes DO aspect to randomize
}
//when button is clicked, quotation function starts
submitButton.onclick = nextQuote;
}
您要在多個位置重新聲明變量,而不是在較高范圍中使用變量,這就是為什么每次都不會獲得新報價的原因。
window.onload = function() {
var quoteSpan = document.getElementById("quoteText");
var authorSpan = document.getElementById("authorText");
var submitButton = document.getElementById('submit');
var oldQuoteIndex = -1;
var newQuoteIndex = -1;
var quotes = [
{'text': '"Whatever you are, be a good one."', 'author': '-Abraham Lincoln'},
{'text': '"It has been my philosophy of life that difficulties vanish when faced boldly."', 'author': '-Isaac Asimov'},
{'text': '"Enjoy life. There’s plenty of time to be dead."', 'author': '-Anonymous'},
{'text': '"Every moment is a fresh beginning."', 'author': '-T.S. Eliot'},
{'text': '"One day your life will flash before your eyes. Make sure it is worth watching."', 'author': '-Anonymous'}
];
function nextQuote() {
while (newQuoteIndex == oldQuoteIndex) {
newQuoteIndex = Math.floor(Math.random() * quotes.length);
}
quoteSpan.innerHTML = quotes[newQuoteIndex].text; //make HTML's quoteText random quote
authorSpan.innerHTML = quotes[newQuoteIndex].author; //make HTML's authorText random author
oldQuoteIndex = newQuoteIndex;
}
submitButton.onclick = nextQuote;
}
/* getNewQuote might be good in a js file to use on any page */
function getNewQuote(callback){
var newquote;
var quotes = getNewQuote.prototype.quotes;
do{
newquote = quotes[parseInt(Math.random()*quotes.length)];
/* if quotes.length == 1 we'll loop forever */
}while( quotes.length > 1 && !getNewQuote.prototype.isLastQuote(newquote));
/* Good idea to check if there is a callback */
if(callback){
callback(newquote);
}
}
getNewQuote.prototype.quotes = [
{'text': '"Whatever you are, be a good one."', 'author': '-Abraham Lincoln'},
{'text': '"It has been my philosophy of life that difficulties vanish when faced boldly."', 'author': '-Isaac Asimov'},
{'text': '"Enjoy life. There’s plenty of time to be dead."', 'author': '-Anonymous'},
{'text': '"Every moment is a fresh beginning."', 'author': '-T.S. Eliot'},
{'text': '"One day your life will flash before your eyes. Make sure it is worth watching."', 'author': '-Anonymous'}
];
getNewQuote.prototype.lastQuote = null;
getNewQuote.prototype.isLastQuote = function(quote){
if(!getNewQuote.prototype.lastQuote
|| ( getNewQuote.prototype.lastQuote.author != quote.author
&& getNewQuote.prototype.lastQuote.text != quote.text )
) {
return getNewQuote.prototype.lastQuote = quote;
}
return null;
}
/* End of the getNewQuote */
/* This goes on the page */
submitButton.onclick = function (){
/* pass getNewQuote a callback function to update the elements with the new quote */
getNewQuote(function(quote){
quoteSpan.innerHTML = quote.text;
authorSpan.innerHTML = quote.author;
});
}
/* if you decide to go with jQuery you can replace the above onclick with this */
$(function(){
$("#submitButton").click(function (){
getNewQuote(function(quote){
$("#quote").html(quote.text);
$("#author").html(quote.author);
});
});
});
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