GET requests are idempotent, meaning that multiple requests for the same URL should return the same result, the client can send a GET request to the server repeatedly without negative effects.
Idempotent (idempotent) is a mathematical concept or computer science.
Idempotent (idempotence)
in mathematics, there are two main power definitions:
1) to unary , if an operator of a number of times for all of the calculation results obtained in the range of the operation and once the the results obtained are the same, then we say that the operation is idempotent.
f(f(x)) = f(x)
For example: absolute value operation is an example, in real numbers concentrated, abs (a) = abs (abs (a)).
2) For the binary operator is required when the two values are involved in computing equivalent case, if the two values satisfy the calculation involved in computing the result is equal, the calculation called idempotent,
For example: selecting the maximum value as a function of the number of two, have focused on the real idempotent, i.e., max (x, x) = x .
Another example: real numbers 0 and 1, multiplication is idempotent s * s = s
Reproduced in: https: //www.cnblogs.com/liuming8080/p/3670732.html