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下面张表里有一些模式与单位的例子，模式里的所有变量都假定未被绑定过。单位就是指任何一种 Erlang 数据结构。
| 模式 = 单元 | 结果 |
| {X,adc} = {123, abc} | 成功: X = 123 |
| {X,Y,Z} = {222,def,"cat"} | 成功: X = 222, Y = def, Z = "cat" |
| {X,Y} = {333,ghi,"cat"} | 失败: 左右两边元组结构不同 |
| X = true | 成功: X = true |
| {X,Y,X} = {{abc,12},42,{abc,12}} | 成功: X = {abc,12}, Y = 42 |
| {X,Y,X} = {{abc,12},42,true} | 失败: X 不能被重复绑定 |
| [H|T] = [1,2,3,4,5] | 成功: H = 1, T = [2,3,4,5] |
| [H|T] = "cat" | 成功: H = 99, T = "at" |
| [A,B,C|T] = [a,b,c,d,e,f] | 成功: A = a, B = b, C = c, T = [d,e,f] |
如果对其中一条不够确定，可以在 Erlang shell 验证。
1> {X, abc} = {123, abc}.
{123,abc}
2> X.
123
3> f().
ok
4> {X,Y,Z} = {222,def,"cat"}.
{222,def,"cat"}
5> X.
222
6> Y.
def
7> Z.
"cat"
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原文地址：http://www.cnblogs.com/mydevops/p/4959337.html
