Lambda expression is an anonymous function without a name, and its syntax is: (parameter_list) -> expression. They feature anonymity, diversity, currying, and closure. In practical applications, lambda expressions can be used to succinctly define functions, such as the summation function sum_lambda = lambda x, y: x y, and apply the map() function to the list to perform the summation operation.
Introduction
Lambda expressions are anonymous functions that provide A concise way to define functions and pass them to other code or store them in variables. Their simplicity makes them very useful in functional programming and stream processing.
Grammar
lambda expression has the following syntax:
(parameter_list) -> expression
Structure
Lambda expression has the following structure:
Features
Lambda expressions have the following characteristics:
Practical case
Consider the following code:
# 创建一个以两个数字为参数并返回其和的 lambda 表达式 sum_lambda = lambda x, y: x + y # 使用 lambda 表达式对列表求和 numbers = [1, 2, 3, 4, 5] total = sum(map(sum_lambda, numbers)) print(total) # 输出:15
In this example,sum_lambda
is a lambda expression Formula, which accepts two parametersx
andy
and returns their sum. Themap()
function uses thesum_lambda
expression to sum each element in thenumbers
list, and finally thesum()
function sums these The sums are added to get the final sum15
.
The above is the detailed content of What are the syntax and structure characteristics of lambda expressions?. For more information, please follow other related articles on the PHP Chinese website!