const list = [...];// 修改 list 中的 type 和 agelist.map(item => {item.type = 1;item.age++;})复制代码 这样函数最主要的输出功能没有了,变成了直接修改了外部变量,这就是它的副作用。而没有副作用的写法应该是: const list = [...];// 修改 list 中的 type 和 ageconst newList = li...
sin of the angle x (given in radians)Math.cos(x) returns the cosin of the angle x (given in radians)Math.max() return the number with the highest value from a list of argumentsMath.min() to return the number with the lowest value from a list of argumentsConverting Celsius to ...
arg1, arg2, ... arg_N_Names to be used by the function as formal argument names. Each must be a string that corresponds to a valid JavaScript identifier or a list of such strings separated with a comma; for example "x", "theValue", or "a,b".functionBodyA string containing the Ja...
Type:string[] Default:['es2021', 'node'] Whichenvironmentsyour code is designed to run in. Each environment brings with it a certain set of predefined global variables. globals Type:string[] Additional global variables your code accesses during execution. ...
In an arrow function, this is equal to the this value of the enclosing execution context. Basically, with arrow functions, you don't have to do the "that = this" trick before calling a function inside a function anymore.function myFunc() { this.myVar = 0; setTimeout(() => { this....
eval (default: false)— mangle names visible in scopes where eval or with are used. reserved (default: [])— when mangling is enabled but you want to prevent certain names from being mangled, you can declare those names with --mangle reserved— pass a comma-separated list of names. For...
The JavaScript methodtoString()converts an array to a string of (comma separated) array values. Example constfruits = ["Banana","Orange","Apple","Mango"]; document.getElementById("demo").innerHTML= fruits.toString(); Result: Banana,Orange,Apple,Mango ...
Run'python manage.py migrate'to apply them. August14,2018-15:25:57Django version2.1, using settings'myxxx.settings'Starting development server at http://127.0.0.1:8000/Quit the server with CTRL-BREAK. 我们在runserver的时候可以指定ip和端口号 G:\mytest>python manage.py runserver 127.0.0.1:8888...
Lines beginning with two forward slashes won’t be processed and you can use them to write anything, comments, instructions, your to-do list, etc.Let’s go on with writing some code. Most of your JavaScript code will be written as functions. Functions are blocks of code you can call ...
The layers on which to perform the identify operation. The layers are specified as a comma-separated list of layer IDs. layerOption Property layerOption String Specifies which layers to use when using Identify. Possible valuesDescription top Only the top-most visible layer on the service i...