How to determine whether a string is a letter in java

Java method to determine whether it is a letter:

/**
     * 判断是否是字母
     * @param str 传入字符串
     * @return 是字母返回true，否则返回false
     */
    public boolean is_alpha(String str) {
        if(str==null) return false;
        return str.matches("[a-zA-Z]+");
    }

Regular expression is a powerful tool for processing strings. It is not a feature of Java. Front-end JavaScript also has . But compared to other old high-level languages, such as C/C, this is where Java is unique than them.

matches() method is used to detect whether a string matches a given regular expression.

Regular expression usage:

1. String matching

2. String search

3. String replacement

For more java knowledge, please pay attention to java basic tutorial.

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