在数学上：
函数就是映射
映射就是函数
映射map,函数function
In mathematics and related technical fields,the term map or mapping is often a synonym for function.Thus,for example,a partial map is a partial function,and a total map is a total function.Related terms like domain,codomain,injective,continuous,etc.can be applied equally to maps and functions,with the same meaning.
映射和函数的本质：
f:A -> B （A到B的映射）
对任意的x属于A,都有唯一的y属于B,使得f(x)=y.
注意“都有”和“唯一” 在数学上：
函数就是映射
映射就是函数
映射map,函数function
In mathematics and related technical fields,the term map or mapping is often a synonym for function.Thus,for example,a partial map is a partial function,and a total map is a total function.Related terms like domain,codomain,injective,continuous,etc.can be applied equally to maps and functions,with the same meaning.
映射和函数的本质：
f:A -> B （A到B的映射）
对任意的x属于A,都有唯一的y属于B,使得f(x)=y.
注意“都有”和“唯一”