add js solution for wordBreak

problems/0139.单词拆分.md

@@ -291,6 +291,27 @@ func wordBreak(s string,wordDict []string) bool  {
 }
 ```
 
+Javascript：
+```javascript
+const wordBreak = (s, wordDict) => {
+
+    let dp = Array(s.length + 1).fill(false);
+    dp[0] = true;
+
+    for(let i = 0; i <= s.length; i++){
+        for(let j = 0; j < wordDict.length; j++) {
+            if(i >= wordDict[j].length) {
+                if(s.slice(i - wordDict[j].length, i) === wordDict[j] && dp[i - wordDict[j].length]) {
+                    dp[i] = true
+                }
+            }
+        }
+    }
+
+    return dp[s.length];
+}
+```
+
 
 
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