统计字符串中某个字符的个数

Posted 2021-01-15 wenlin-gk

    private int countNum(final String str, final char ch){
        int num = 0;
        if (str != null){
            for(char i: str.toCharArray()){
                if(i==ch){
                    ++num;
                }
            }
        }
        return num;
    }