Skip to main content

Learning to use js template strings.

 Why does js introduce template strings?

  • This new feature was added in ES6, which means that js also supports templates, which are represented by backticks `.Called a string literal, it's a template string. It gives JS a simple string interpolation feature as well. Why is it simple, because it can't automatically escape special characters, it can't handle dates, times, etc. in special language formats, and it doesn't support looping.Currently it's just something that handles output strings, not a replacement for a template engine.

  • Let's get to know it together.

  • Insert variables in template strings.
Traditional string concatenation uses +, which is very cumbersome, but now, with ES6 syntax, string concatenation can be written like this:
  var a="123";
        var b="hello"+a+"hhh"+a;//before
        var c=`hello${a}hhh${a}`;//now
        console.log(c)
  • Line breaks are allowed in template strings.
Template strings support newlines, which makes the code very nice and clear.
 let str=`<ul>
                <li>${xxx}</li>
                <li>${xxx}</li>
                <li>${xxx}</li>
            </ul>`;
  • Template strings support nested use, as well as the use of expressions.
    let array= [
    {
      id: 1001,
      name: "aaa"
    },
    {
        id:1002,
        name:"bbb"
    }
  ]
 
  const str = `
    <ul>
      ${array.map((item)=>`
      <li>
        ${item.id} ,${item.name?333:0000}}
      </li>
      `)}
    </ul>
  `
  console.log(str);
  • Functions can be called in template strings. The position in the string where the function is called will display the return value after the function is executed.
function fun(){
    return "666";
  }
  console.log(`hello${fun()}-111`);
Summary: A total of four usage scenarios have been introduced above, and more usage scenarios need to be explored by yourself!

Comments

Popular posts from this blog

Native ajax usage

 What is AJAX? AJAX stands for "Asynchronous Javascript And XML" (Asynchronous JavaScript and XML), which refers to a web development technology for creating interactive web applications for data interaction between browsers and servers. AJAX uses asynchronous data transfer (HTTP requests) between the browser and the web server, which allows web pages to request small amounts of information from the server instead of the entire page. AJAX describes a web application architecture that mainly uses scripts to manipulate HTTP. The main feature of AJAX applications is to use scripts to manipulate HTTP and web servers for data exchange without causing page reloads. Simply put, without reloading the entire web page, AJAX loads data in the background and displays it on the web page, which can partially refresh the page. The user has a better experience using the web page, but cannot go back.

What is the difference between the box-size property content-box and border-box in the css box model?

 The box model is a very important concept in CSS layout, it includes content area, padding, border, and margin. Box models can be divided into two types: standard box models and IE box models. The box model, as the name suggests, is used to hold things, and the things it holds are the content of HTML elements. In other words, every visible HTML element is a box.

vue routing global guard beforeEach and afterEach

 Global routing front guard (beforeEach) This function is used the most. Its function is to perform permission-related verification before routing jumps. This function contains three parameters: to: the object of the target route that is about to enter; from: the route that the current route is leaving; next: confirm the release. It can be used to log in and register, to determine whether there is a token before logging in, and release if it exists. , if it does not exist, it will not be released. The post routing guard (afterEach), its role is to trigger after the routing jump.