Simple and readable solution using JavaScript Set()
\nvar uncommonFromSentences = function(A, B) {\n    const wordSet = new Set();\n    const removed = new Set();\n    const combined = `${A} ${B}`.split(" ");\n  
```\nvar uncommonFromSentences = function(A, B) {\n    const wordSet = new Set();\n    const removed = new Set();\n    const combined = `${A} ${B}`.split(" ");\n    \n    for (let word of combined) {\n        if (wordSet.has(word) || removed.has(word)) {\n            wordSet.delete(word);\n            removed.add(word);\n        } else {\n            wordSet.add(word);\n        }\n    }\n    return [...wordSet];\n};\n```
['JavaScript']