[12.1.理解Lambda](12.1.%E7%90%86%E8%A7%A3Lambda.md) [12.2.使用Lambda](12.2.%E4%BD%BF%E7%94%A8Lambda.md) [12.3.Predicates](12.3.Predicates.md) [12.4.考试问题举例](12.4.%E8%80%83%E8%AF%95%E9%97%AE%E9%A2%98%E4%B8%BE%E4%BE%8B.md)