functionfoo(){vara=1varf1=function(){returna}vara=2varf2=function(){returna}return{f1:f1,f2:...
ES6里已经支持默认参数了,直接写就好啦: functionmultiply(a, b =1) { returna*b; }multiply(5);// 5 ES6还支持解构赋值来设置默认参数: jQuery.ajax=function(url, {async=true, beforeSend =function() {}, cache =true, complete =function() {}, crossDomain =false,global=true, // ... more ...
In this example, thegreet()function has a default parameternamewith the string valueGuest. Since we have not passed any argument to the function, it uses the default value. Example: JavaScript Default Parameters functionsum(x =3, y =5){// return sumreturnx + y; } // pass arguments to...
); } // store a function in the displayPI variable // this is a function expression let displayPI = function() { console.log("PI = 3.14"); } // call the greet() function greet(); // call the reply() function displayPI(); // Output: // Hello World! // PI = 3.14 Run Cod...
First, declare asum()function with multiple default parameters: // Define a function to add two valuesfunctionsum(a=1,b=2){returna+b}sum() Copy This will result in the following default calculation: Output 3 Additionally, the value used in a parameter can be used in any subsequent defaul...
If a function is called withmissing arguments(less than declared), the missing values are set toundefined. Sometimes this is acceptable, but sometimes it is better to assign a default value to the parameter: Example functionmyFunction(x, y) { ...
functionsettings(options={}){const{theme,debug}=options// Do something with settings} 这样避免因解构不存在的对象而导致的错误。 现在我们已经看到了默认参数如何与不同的数据类型一起工作,下面我们来看看多个默认参数如何协同工作。 使用多个默认参数
public JavaScriptFunctionRetrieveDefaultDefinitionParameters withUdfType(UdfType udfType) Legen Sie den udfType-Wert fest. Parameter: udfType- der festzulegende udfType-Wert Gibt zurück: das JavaScriptFunctionRetrieveDefaultDefinitionParameters-Objekt selbst. ...
“‘{a}’ is a function.”:“‘{a}’是一个函数”, ‘Bad assignment.’:“错误的赋值”, “Do not assign to the exception parameter.”:“不要给额外的参数赋值”, “Expected an identifier in an assignment and instead saw a function invocation.”:“在赋值的语句中需要有一个标识符,而不是一...
“Use the isNaN function to compare with NaN.”:“使用isNaN来与NaN比较”, “Confusing use of ‘{a}’.”:“容易混淆的’{a}’的使用”, “Read only.”:“只读的属性”, “‘{a}’ is a function.”:“‘{a}’是一个函数”,