我在for循环之上的函数中声明了变量 highScore = 0 ，当我尝试在内部声明相同的变量（highScore = 0）时我做了相同的功能 for loop 。在这两种情况下，输出都是不同的。以下是我的代码。
/*
i = [0, 1, 2, 3, 4, 5,
6, 7, 8, 9, 10, 11,
12, 13, 14, 15, 16, 17,
19, 20, 21, 22, 23, 24,
25, 26, 27, 28, 29, 30,
31, 32, 33, 34, 35]
*/
var scores = [60, 50, 60, 58, 54, 54,
58, 50, 52, 54, 48, 69,
34, 55, 51, 52, 44, 51,
69, 64, 66, 55, 52, 61,
46, 31, 57, 52, 44, 18,
41, 53, 55, 61, 51, 44];
function printandgetHighScore(scores) {
var highScore = 0;
var output;
for (var i = 0; i < scores.length; i++) {
output = "Bubble solution # " + i + "scores: " + scores[i];
console.log(output);
if(scores[i] > highScore) {
highScore = scores[i];
}
}
return highScore;
}
var highScore = printandgetHighScore(scores);
console.log("Bubbles tests: " + scores.length);
console.log("Highest bubble score: " + highScore);
var bestSolutions = [];
for (var i = 0; i < scores.length; i++) {
if (scores[i]== highScore) {
bestSolutions.push(i);
}
}
console.log("Solutions with the highest score: " + bestSolutions);
Output when the **variable highScore = 0; inside function and above for loop**
Bubble solution # 0scores: 60 bubble.js:29
Bubble solution # 1scores: 50 bubble.js:29
Bubble solution # 2scores: 60 bubble.js:29
Bubble solution # 3scores: 58 bubble.js:29
Bubble solution # 4scores: 54 bubble.js:29
Bubble solution # 5scores: 54 bubble.js:29
Bubble solution # 6scores: 58 bubble.js:29
Bubble solution # 7scores: 50 bubble.js:29
Bubble solution # 8scores: 52 bubble.js:29
Bubble solution # 9scores: 54 bubble.js:29
Bubble solution # 10scores: 48 bubble.js:29
Bubble solution # 11scores: 69 bubble.js:29
Bubble solution # 12scores: 34 bubble.js:29
Bubble solution # 13scores: 55 bubble.js:29
Bubble solution # 14scores: 51 bubble.js:29
Bubble solution # 15scores: 52 bubble.js:29
Bubble solution # 16scores: 44 bubble.js:29
Bubble solution # 17scores: 51 bubble.js:29
Bubble solution # 18scores: 69 bubble.js:29
Bubble solution # 19scores: 64 bubble.js:29
Bubble solution # 20scores: 66 bubble.js:29
Bubble solution # 21scores: 55 bubble.js:29
Bubble solution # 22scores: 52 bubble.js:29
Bubble solution # 23scores: 61 bubble.js:29
Bubble solution # 24scores: 46 bubble.js:29
Bubble solution # 25scores: 31 bubble.js:29
Bubble solution # 26scores: 57 bubble.js:29
Bubble solution # 27scores: 52 bubble.js:29
Bubble solution # 28scores: 44 bubble.js:29
Bubble solution # 29scores: 18 bubble.js:29
Bubble solution # 30scores: 41 bubble.js:29
Bubble solution # 31scores: 53 bubble.js:29
Bubble solution # 32scores: 55 bubble.js:29
Bubble solution # 33scores: 61 bubble.js:29
Bubble solution # 34scores: 51 bubble.js:29
Bubble solution # 35scores: 44 bubble.js:29
Bubbles tests: 36 bubble.js:41
**Highest bubble score: 69 bubble.js:42
Solutions with the highest score: 11,18 bubble.js:55**
And only difference when i declare the variable **highScore = 0;** inside the function
**inside for loop** i get output is
**Highest bubble score: 44 bubble.js:42
Solutions with the highest score: 16,28,35**
答案 0 :(得分：0)
全局变量名scores与printandgetHighScore函数内传递的变量名称不匹配。试试这个：
function printandgetHighScore(_scores) {
var highScore = 0;
var output;
for (var i = 0; i < _scores.length; i++) {
output = "Bubble solution # " + i + "scores: " + _scores[i];
console.log(output);
if(_scores[i] > highScore)
highScore = _scores[i];
}
return highScore;
}
答案 1 :(得分：0)
当在循环内声明highScore时，其值在每次迭代中重置为零。这就是为什么最后你会看到highScore的值为44，这是数组中的最后一个元素。将它声明在循环上方以使其工作。这样，分配的先前值将保持不变，不会重置为0.
答案 2 :(得分：0)
当你在循环中使用highScore = 0时，它会在循环的每次迭代中重置为0。这意味着与其进行比较的下一个得分（即下一个数组项）将始终高于它，并且将被视为迄今为止的最高得分。这会一直重复，直到最后一个数组项，它成为highScore的最后一个值 - 导致最终数组项（44）得分最高的错误结论。
在循环外声明highScore是正确的方法，这会导致记录真正的最高分。这是一个实现您的代码的JSFiddle，以及它的错误版本。请注意，在printandgetHighScoreIncorrect()中，变量在for循环内不断重新声明，导致最后一个数组项44为＆＃34;高分＆＃34;。尝试更改数组的最后一项，您应该看到与该函数的输出直接相关。
希望这会有所帮助。如果您有任何问题，请告诉我们！