A data model, called the entity-relationship model, is proposed. This model incorporates some of the important semantic information about the real world.

代码如下: //by ppchen var a = 10, b = 2; a = a + b; b = a – b; a = a – b; 代码如下: //by Mr.司马 var a = 10000,b=245 a = a^b; b = b^a; a = a ^b; 代码如下: //by cloudgamer var a = 33,b=44 a=[a,b] b=a[0] a=a[1] 代码如下: //by Mr.司马 var a = 23,b=454; a = {a:b,b:a};