📌  相关文章
📜  ES6-对象扩展

📅  最后修改于: 2020-10-25 10:47:08             🧑  作者: Mango

字符串扩展

在ES6中添加到String对象的一些流行方法是-

Sr.No Method & Description
1 str.startsWith(searchString[, position])

determines whether a string begins with the characters of a specified string. Returns true or false
2 str.endsWith(searchString[, length])

determines whether a string ends with the characters of a specified string. Returns true/false
3 str.includes(searchString[, position])

determines whether one string may be found within another string
4 str.repeat(count)

constructs and returns a new string which contains the specified number of copies of the string on which it was called, concatenated together

正则表达式扩展

在正则表达式中，例如/ [AZ] / g ，开始和结束/称为定界符。结束定界符之后的任何内容都称为修饰符。 ES6添加了一个新的修饰符/ g ，其中g代表global 。这将匹配字符串模式的所有实例，而不仅仅是一个。

例

以下示例搜索并返回字符串所有大写字符。

上面代码的输出如下：

["J", "J", "F", "W", "F"]

正则表达式搜索区分大小写。若要关闭区分大小写，请使用/ i修饰符。

例

以下示例执行不区分大小写的全局匹配。该示例将乐趣替换为愉快。

上面代码的输出将如下所示-

Javascript is enjoyable to Work , very enjoyable
Javascript is fun to Work , very Fun
15

数

在ES6中添加到Number对象的一些流行方法是-

Sr.No Method & Description
1 Number.isFinite(value)

method determines whether the passed value is a finite number. Returns true/false.
2 Number.isNaN(value)

returns true if the given value is NaN and its type is Number; otherwise, false.
3 Number.parseFloat(string)

A floating-point number parsed from the given value. If the value cannot be converted to a number, NaN is returned.
4 Number.parseInt(string,[ radix])

method parses a string argument and returns an integer of the specified radix or base.

数学

在ES6中添加到Math对象的一些流行方法是-

Sr.No Method & Description
1 Math.sign()

function returns the sign of a number, indicating whether the number is positive, negative or zero.
2 Math.trunc()

function returns the integer part of a number by removing any fractional digits.

ES6中的数组方法

下表给出了ES6中不同的数组方法及其说明。

Sr.No Method & Description
1 copyWithin()

shallow copies part of an array to another location in the same array and returns it without modifying its length.
2 entries()

method returns a new Array Iterator object that contains the key/value pairs for each index in the array.
3 find()

method returns the value of the first element in the array that satisfies the provided testing function. Otherwise undefined is returned..
4 fill()

method fills all the elements of an array from a start index to an end index with a static value. It returns the modified array.
5 Array.of()

method creates a new Array instance from a variable number of arguments, regardless of number or type of the arguments.
6 Array.from()

method creates a shallow copy from an array like or iterable object.

目的

下表中提及了与对象函数有关的方法以及相应的说明。

Sr.No Method & Description
1 Object.is()

method determines whether two values are the same value
2 Object.setPrototypeOf()

method sets the prototype of a specified object to another object or null.
3 Object.assign()

method is used to copy the values of all enumerable own properties from one or more source objects to a target object. It will return the target object.