如何用forEach替代for循环

huangapple go评论67阅读模式
英文:

how to replace for loop by forEach

问题

String Number = "123";
boolean NumberPresent = false;
List<Summary> smryList = smryListResponse.getSummaryList();

for (Summary summary : smryList) {
    if (Number.equals(summary.getNumber())) {
        NumberPresent = true;
        break;
    }
}
if (NumberPresent) {
   //perform some actions
}
英文:

My code is,

String Number = &quot;123&quot;;
boolean NumberPresent = false;
List &lt; Summary &gt; smryList = smryListResponse.getSummaryList();

for (int i = 0; i &lt; smryList.size(); i++) {
    if (Number.equals(smryList.get(i).getNumber())) {
        NumberPresent = true;
        break;
    }
}
if (NumberPresent) {
   //perform some actions
}

How can I replace this complete for loop functionality with forEach?

答案1

得分: 5

for (Summary summary: smryList) {
    if (Number.equals(summary.getNumber())) {
        NumberPresent = true;
        break;
    }
    // ...
}
英文:

this way you can apply for-each loop.

for (Summary summary: smryList) {
    if (Number.equals(summary.getNumber())) {
        NumberPresent = true;
        break;
    }
    // ... 
}

答案2

得分: 2

你不需要使用 forforEach 来检测数字是否存在。你可以使用流以及 .anyMatch() 方法。例如:

String number = "123";    
List<Summary> smryList = smryListResponse.getSummaryList();
boolean isNumberPresent = smryList
                           .stream()
                           .anyMatch(summary -> summary.getNumber().equals(number));
if (isNumberPresent) {
    // ...
}

另外,你也可以尝试使用其他流方法,比如 .filter() 或其他方法。但我更倾向于使用 .anyMatch()

备注: 流和 Lambda 表达式仅适用于 Java 8 或更新版本。
否则,请使用已发布的 解决方案

英文:

You don't need to use for or forEach if you want to detect is number presented. You can use streams with i.e. .anyMatch() method.
In example:

String number = &quot;123&quot;;    
List&lt;Summary&gt; smryList = smryListResponse.getSummaryList();
boolean isNumberPresent = smryList
                           .stream()
                           .anyMatch(summary -&gt; summary.getNumber().equals(number));
if (isNumberPresent) {
    // ...
}

Also, you can try do that with other stream methods, i.e. .filter() or other. But I prefer to use .anyMatch().
>Remark: streams and lambda expressions works only with Java 8 or later.
>Otherwise use already posted solution

答案3

得分: 0

你可以用这个循环替换for循环。

for (Summary summary : smryList) {
    if (Number.equals(summary.getNumber())) {
        NumberPresent = true;
        break;
    }
}

另外,你可以尝试使用以下方式:

smryList.forEach(summary -> {// 在这里编写代码
});
英文:

you can replace the for loop with this loop.

 for (Summary summary : smryList) {
            if (Number.equals(summary.getNumber())) {
                NumberPresent = true;
                break;
            }
        }

otherwise, you can try

smryList.forEach(summary -&gt; {//code here
        });

huangapple
  • 本文由 发表于 2020年10月23日 13:28:12
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