「Ruby筆記05」基礎語法2

count 方法

用來計算陣列之中的元素或是某指定元素的數量。

  
    nums = [0,2,4,0,3,0]
    nums.count <span class="com"># 單純計算陣列元素數量。得6</span>
    nums.count(0) <span class="com"># 計算陣列中0的數量。得3</span>
    nums.count{|x| x - 2 > 0} <span class="com"># 計算陣列中某元素「x」，且此元素符合「x - 2 > 0」。得2</span>
  

include 方法

掃描變數是否包含某項元素。

  
    super.include?"s" <span class="com"># 回傳true。</span>
  

gsub 方法

替換變數中的某元素

  
    super.gsub!(/s/, "th") <span class="com"># 將「//」中的元素變換成「""」中的元素。</span>
  

split 方法

將字串拆解成陣列。

  
    "super man".split <span class="com"># ["super", "man"]</span>
    " super man".split("") <span class="com"># [" ","s","u","p","e","r"," ","m","a","n"]</span>
    " super man".split(//) <span class="com"># [" ","s","u","p","e","r"," ","m","a","n"]</span>
    " super man".split(" ") <span class="com"># ["super", "man"]</span>
    " super man".split(/ /) <span class="com"># ["","super", "man"]</span>


    "super".split(//, 3) <span class="com"># ["s", "u", "per"]</span>
    "super man".split(//, 3) <span class="com"># ["s", "u", "per man"]</span>


    "super super".split("upr") <span class="com"># ["s", "r s", "r"]</span>
    "1,2,,3,4,,".split(',') <span class="com"># ["1", "2", "", "3", "4"]</span>
    "1,2,,3,4,,".split(',', 4) <span class="com"># ["1", "2", "", "3,4,,"]</span>
    "1,2,,3,4,,".split(',', -4) <span class="com"># ["1", "2", "", "3", "4", "", ""]</span>
    "".split(',', -1) <span class="com"># []