我似乎无法列出数组中偶数的数量，而且当我将数组整数乘以乘数时也无法得到结果。我已经想了很长时间了，我无法再思考了。提前致谢!
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title>EvensMultiply</title>
<script type="text/javascript">
/*Write a defining table and a function named countEvens that counts and returns the number of even integers in an array. The function must have this header: function countEvens(list)*/
// This function will call and test countEvens() and multiply(list, multiplier).
function testFunctions() {
var list = [17, 8, 9, 5, 20];
var multiplier = 3;
var result1 = 0;
var result2 = 0;
var result3 = 0;
result1 = countEvens(list);
//result2 = multiply(list, multiplier);
result3 = "These are the even numbers of the array list: " + result1 + "<br>" + "This is the array list multiplied by 3: " + result2;
document.getElementById("outputDiv").innerHTML = result3;
}
// This function will find the even intergers in the array.
function countEvens(list) {
var evens = [];
for (var i = 0; i < list.length; ++i) {
if ((list[i] % 2) === 0) {
evens.push(list[i]);
return evens;
}
}
}
/*Write a defining table and a function to multiply each element in an array by some value. The function must have this header: function multiply(list, multiplier)*/
// This function will multiply the array list by a multiplier.
function multiply(list, multiplier) {
var products;
products=list.map(function(list){return list * multiplier;});
return products;
}
</script>
</head>
<h1>Find evens and multiply by multiplier.</h1>
<h2>Array list [17, 8, 9, 5, 20]</h2>
<h3>Click the Compute button to test.</h3>
<button type="button" onclick="testFunctions()">Compute</button>
<div id="outputDiv"></div>
</html>
最佳答案
循环完成后需要返回:
// This function will find the even intergers in the array.
function countEvens(list) {
var evens = [];
for (var i = 0; i < list.length; ++i) {
if ((list[i] % 2) === 0) {
evens.push(list[i]);
}
}
return evens;
}
关于javascript - 数组 数学逻辑 JavaScript，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/34191397/