68 lines
2.1 KiB
Markdown
68 lines
2.1 KiB
Markdown
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---
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title: Template Literals
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---
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## Template Literals
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## Introduction:
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When we want to use variable to make a string, it becomes very painful as we have to use + sign to concatenate and keep track of quotes.
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Now with ES6,We can make string using backticks and using placeholders which are indicated with dollar sign and curly braces, like ${expression } .
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```javascript
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const name='John';
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const city='London';
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Older Style:
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const sentence ='My name is '+ name +'. I live in '+city.
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ES6 way:
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const sentence = `My name is ${name}. I live in ${city}`;
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Here ${name} and ${city}are going to be interpolated by the variable name and city respectively.
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```
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## MultiLine Strings:
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Older style:
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When we wanted to span our string into multiple lines, we had to use backslashes.
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```javascript
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const multipleLineString= "We have \
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multiple lines \
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here";
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```
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Now when we want to create a mutiline string, we can make use of template strings.We can surround our string with backticks. This approach is extremely helpful when we want to create some dynamic html markup.
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```javascript
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const htmlMarkup = `
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<html>
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<head></head>
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<title>Template string</title>
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<body>Hello World</body>
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</html>`;
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```
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## Nesting of Template Strings:
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We can nest them inside of each other.
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```javascript
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const cities =[
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{name:'Delhi', year: 2010},
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{name:'Mumbai', year: 2015},
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{name:'Kolkata', year: 2017}];
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const markup = `
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<ul>
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${cities.map(city=>`<li>I lived in ${city.name} in the year ${city.year}</li>`).join('')}
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</ul>`;
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```
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Here the join operator after map function removes the extra commas which are added after each li.
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## If statements and Functions
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We can also use If statements inside the template strings.
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```javascript
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const data = {name: 'John', city: 'London', birthyear: 1900};
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const markup = `<div>${data.name} lives in ${data.city}. ${data.birthyear ? `<div>He was born in the year ${data.birthyear}</div>`:''}</div>`;
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```
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In the example above, if birthyear is defined, then div with contents "He was born in the year" is generated otherwise there would be no div created.
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We can also call functions inside the template strings.
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