151. Reverse Words in a String（js）

151. Reverse Words in a String

Given an input string, reverse the string word by word.

Example 1:

Input: "the sky is blue"
Output: "blue is sky the"
Example 2:

Input: "  hello world!  "
Output: "world! hello"
Explanation: Your reversed string should not contain leading or trailing spaces.
Example 3:

Input: "a good   example"
Output: "example good a"
Explanation: You need to reduce multiple spaces between two words to a single space in the reversed string.
 

Note:

A word is defined as a sequence of non-space characters.
Input string may contain leading or trailing spaces. However, your reversed string should not contain leading or trailing spaces.
You need to reduce multiple spaces between two words to a single space in the reversed string.

题意：给定一个句子，反转句子的单词，首尾空格剔除，单词间空格保持一个空格

代码如下：

/**
 * @param {string} s
 * @return {string}
 */
var reverseWords = function(s) {
//     通过空格切割字符串
    let sarr=s.split(' ');
    let arr=[];
    for(let i=0;i<sarr.length;i++){
//         将空字符串项全部筛除
        if(sarr[i]!==''){
            arr.unshift(sarr[i]);
        }
    }
//     通过空格合并数组项
    return arr.join(' ');
};