给定字符串数组，输出由每个字符串前两个字符组成的数组

给定一个字符串数组，输出一个新数组，其中每个元素为原数组对应字符串的前两个字符。
示例输入：a = ["dog","horse","transform","take"]
示例输出：a = ["do","ho","tr","ta"]

解决方法 #

Python #

用列表推导式简洁处理：

a = ["dog","horse","transform","take"]
new_arr = [s[:2] for s in a]
print(new_arr)  # 输出: ['do', 'ho', 'tr', 'ta']

JavaScript #

借助数组的map方法实现：

const a = ["dog","horse","transform","take"];
const newArr = a.map(str => str.slice(0, 2));
console.log(newArr);  // 输出: ["do", "ho", "tr", "ta"]

补充说明 #

• 若原数组里有长度小于2的字符串（比如["hi", "a", ""]），截取后会保留现有字符（结果为["hi", "a", ""]），不会抛出异常

内容的提问来源于stack exchange，提问作者Иван Новиков