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; //第一种:List result = Arrays.asList(args).contains(str); //第二种:set Set<String> sets = new HashSet<String>(Arrays.asList(args)); result = sets.contains(str); //第三种:loop for (String s : args) { if (s.equals(str)){ return true; } } //第四种:binarySearch(Arrays的binarySearch方法必须应用于有序数组) 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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