A brief discussion on JavaScript strings and arrays_javascript skills

JavaScript String

A string is a collection of characters, including English letters, punctuation marks, special symbols, Chinese characters, etc.

In JavaScript, strings can be represented using double quotes (" ") or single quotes (' ').

Double quotes and single quotes must appear in pairs. Double quotes can contain single quotes, and single quotes can also contain double quotes.

For example:

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var myStr1=" My name is ' xiaohua ' ! ";
var myStr2=' " This is my dream ! " , Tom said. ' ;

The length of the string is obtained by length, for example:

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myStr1.length;
myStr2.length;

JavaScript Array

Arrays are used to store a series of values ​​in separate variables.

In JavaScript, arrays can be defined in the following ways.

Use keyword new to create array objects

For example, create an array named myArray and assign a value:

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var myArray=new Array();
myArray[0] = " zhangming ";
myArray[1] = " zhaowei ";
myArray[2] = " wanghua ";

You can also assign values ​​while creating the object:

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var myArray=new Array(" zhangming " , " zhaowei " , " wanghua ");

Use [ ] to create an array directly

For example, create an array named myArray and assign a value:

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var myArray=[];
myArray[0] = " zhangming ";
myArray[1] = " zhaowei ";
myArray[2] = " wanghua ";

Of course, you can also assign values ​​while creating the array:

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var myArray=[ " zhangming " , " zhaowei " , " wanghua " ];

Create an array of key/value pairs

For example, create an array named myArray and assign a value:

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var myArray=new Array(); // You can also use var myArray=[ ];
myArray["zhangming"] = " 22 ";
myArray["zhaowei"] = " 21 ";
myArray["wanghua"] = " 30 ";

Modify array

Arrays can be modified after creation and assignment, for example:

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myArray[0] = " zhangming_1 ";
myArray[1] = " zhaowei_1 ";
myArray["zhangming"] = " 42 ";
myArray["zhaowei"] = " 61 ";

Array length

In JavaScript, use length to get the array length, for example:

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myArray.length

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