统计字符串中去除空格各个字符出现的个数

    val text = "This is A Text!"
    Observable.from(text.toCharArray().asIterable())
            .filter { !it.isWhitespace() }
            .groupBy { it }
            .map {
                o ->
                o.count().subscribe {
                    println("${o.key}:${it}")
                }
            }
            .subscribe()

打印结果

TIM截图20170717175323.png