java 数组中元素的总和
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Sum of elements in an array
提问by NoobCoderChick
I'm working on a simple assignment for a summer java course and was just hoping you guys could take a look at my code and see if the way I did it is the best way. The purpose is to create a simple intarray with at least 25 elements and use a loop to traverse it and add up all the elements. I had some issues but looks like I got it to work. After I work it out I did a little research and saw some similar stuff where people were using a For Each loop (enhanced loop). Would that be a better option? I'm kinda confused on the best ways to use that opposed to a regular for loop.
我正在为暑期 Java 课程做一个简单的作业，只是希望你们能看看我的代码，看看我的方法是否是最好的方法。目的是创建一个int至少包含 25 个元素的简单数组，并使用循环遍历它并将所有元素相加。我遇到了一些问题，但看起来我已经开始工作了。在我解决之后，我做了一些研究，看到了一些类似的东西，人们在使用 For Each 循环（增强循环）。那会是一个更好的选择吗？我对使用与常规 for 循环相反的最佳方法感到困惑。
Anyway, any comments or criticism in helping me be a better programmer!
无论如何，任何有助于我成为更好程序员的评论或批评！
public class Traversals {
public static void main(String[] args) {
int absenceTotal = 0;
// initialize array with 30 days of absences.
int absencesArr[] = { 1, 3, 0, 9, 8, 23, 1,
11, 23, 5, 6, 7, 10, 1, 5,
14, 2, 4, 0, 0, 1, 3, 2, 1,
1, 0, 0, 1, 3, 7, 2 };
for (int i = 0; i < absencesArr.length; i++) {
absencesArr[i] += absenceTotal;
absenceTotal = absencesArr[i];
}
System.out.println("There were " + absenceTotal + " absences that day.");
}
}
回答by Elliott Frisch
Don't modify the array. I would prefer the for-eachloop. And you should consider that there may be a very large number of students, so I would probably use a longfor sum. And formatted output. Putting that together into something like
不要修改数组。我更喜欢for-each循环。而且您应该考虑到可能有非常多的学生，所以我可能会使用longfor sum。并格式化输出。把它放在一起变成类似的东西
long sum = 0;
for(int i : absencesArr) {
sum += i;
}
// System.out.println("There were " + sum + " absences that day.");
System.out.printf("There were %d absences that day.%n", sum);
回答by Josua Marcel Chrisano
public class Traversals {
public static void main(String[] args) {
int absenceTotal = 0;
// initialize array with 30 days of absences.
int absencesArr[] = { 1, 3, 0, 9, 8, 23, 1,
11, 23, 5, 6, 7, 10, 1, 5,
14, 2, 4, 0, 0, 1, 3, 2, 1,
1, 0, 0, 1, 3, 7, 2 };
for (int i = 0; i < absencesArr.length; i++) {
// remove this
//absencesArr[i] += absenceTotal;
absenceTotal += absencesArr[i]; //add this
}
System.out.println("There were " + absenceTotal + " absences that day.");
}
}
回答by fetta
In Java 8 you can use stream api:
在 Java 8 中，您可以使用流 api：
public class Traversals {
public static void main(String[] args) {
int absenceTotal = 0;
// initialize array with 30 days of absences.
int absencesArr[] = { 1, 3, 0, 9, 8, 23, 1,
11, 23, 5, 6, 7, 10, 1, 5,
14, 2, 4, 0, 0, 1, 3, 2, 1,
1, 0, 0, 1, 3, 7, 2 };
absenceTotal = IntStream.of(array).sum();
System.out.println("There were " + absenceTotal + " absences that day.");
}
}
回答by sushmitha shenoy
shortest way i know would be :
我知道的最短方法是：
int sum=Arrays.stream(absencesArr).sum();
回答by maytham-???????
In addition to other nice contributions, I am fan of for-each loopand will typically do it in one line.
除了其他不错的贡献之外，我很for-each loop喜欢并且通常会在一行中完成。
for(int i : absencesArr) absenceTotal += i;
System.out.printf("There were %d absences that day.", absenceTotal);
But in some situations when I want to have control over my Object size/length/count, I will use for looplike following example:
但是在某些情况下，当我想控制对象大小/长度/计数时，我将使用for loop如下示例：
for (int i = 0; i < absencesArr.length; i++) absenceTotal += absencesArr[i];
System.out.printf("There were %d absences that day.", absenceTotal);
And if I need to have more then one line of codes inside the for loopor for-each loopthen I will put them all inside curly brackets { more than one line of code }.
如果我需要有更多的，然后里面的代码的一行for loop或for-each loop然后我会把他们都内大括号{ more than one line of code }。
