Java determines whether an array contains a certain value
Nov 14, 2019 am 09:20 AM
java determines whether an array contains a certain value
I believe you often check when operating Java Does an array (unordered) contain a specific value? This is a frequently used and very useful operation in Java.
Four methods are given below. The most efficient one is the loop method. If you are interested, you can test it:
public boolean findStr(String[] args,String str){
boolean result = false;
//第一種：List
result = Arrays.asList(args).contains(str);
//第二種：set
Set<String> sets = new HashSet<String>(Arrays.asList(args));
result = sets.contains(str);
//第三種：loop
for (String s : args) {
if (s.equals(str)){
return true;
}
}
//第四種：binarySearch(Arrays的binarySearch方法必須應用于有序數(shù)組)
int res = Arrays.binarySearch(args, str);
if (res > 0){
return true;
}
return result;
}The Arrays.binarySearch method has limitations and must be applied to ordered arrays. . It is recommended to use a loop to judge, which is highly efficient.
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