};// create object literals for the different sizesvarsmall = {getPrice:function(){returnthis.basePrice+2},getLabel:function(){returnthis.name+' small'} };varmedium = {getPrice:function(){returnthis.basePrice+4},getLabel:function(){returnthis.name+' medium'} };varlarge = {getPrice:func...
For example, to find the largest number in an array of numbers, you could use the apply() method to pass the elements of the array to the Math.max() function: var biggest = Math.max.apply(null, array_of_numbers);
Write a JavaScript function to get the last element of an array. Passing the parameter 'n' will return the last 'n' elements of the array. Test Data: console.log(last([7, 9, 0, -2])); console.log(last([7, 9, 0, -2],3)); console.log(last([7, 9, 0, -2],6)); Expec...
return -x; // the comparison is false. } // Curly braces optional when 1 statement per clause. } // Note return statements nested inside if/else. abs(-10) === abs(10) // => true function sum(array) { // Compute the sum of the elements of an array let sum = 0; // Start ...
return super.set(key, value); } } TypedMap()构造函数的前两个参数是期望的键和值类型。这些应该是字符串,比如“number”和“boolean”,这是typeof运算符返回的。你还可以指定第三个参数:一个包含[key,value]数组的数组(或任何可迭代对象),指定地图中的初始条目。如果指定了任何初始条目,构造函数首先验证...
arr=arr||[];for(varpropertyin obj) { arr.push(property); }returnarr; } 需要注意的是,当使用这种可选实参来实现函数时,需要将可选实参放在实参列表的最后。一般来书,函数定义中使用注释/*optional*/来强调形参是可选的。 实参对象 当调用函数时传入的参数个数超过了原本函数定义的形参个数,那么方法中可...
numberUsing NaN in a mathematical operation will always return NaNUsing NaN in a mathematical string operation will concatenate NaNNaN (Not a Number) is a number (Yes! typeof NaN returns number)Infinity is returned if you calculate a number outside the largest possible numberDivision by zero als...
arr[x] = arr[largest]; arr[largest] = temp; heapify(arr, largest, len); } } else { return 'arr is not an Array or x is not a number!'; } } 算法分析 调堆:O(h) 建堆:O(n) 循环调堆:O(nlogn) 总运行时间T(n) = O(nlogn) + O(n) = O(nlogn)。对于堆排序的最好情况与...
foo].map(bar); // good const baz = Array.from(foo, bar);4.7 Use return statements in array method callbacks. It’s ok to omit the return if the function body consists of a single statement returning an expression without side effects, following 8.2. eslint: array-callback-return // ...
E Returns Euler's number (approx. 2.718) Math endsWith() Checks whether a string ends with specified string/characters String entries() Returns a key/value pair Array Iteration Object Array error() Outputs an error message to the console Console escape() Deprecated in version 1.5. Use encode...