Angular built-in Slice Pipe | Array SlicePipe + String SlicePipe Example

In the tutorial, we show how to work with Angular impure built-in SlicePipe to create a new Array or String containing a subset of the elements.

Related posts:
– Angular Built-in KeyValue Pipe
– Angular Built-in DatePipe
– Angular Custom Pipe | Pure Pipe + Impure Pipe
– Angular 6 Service – with Observable Data for Asynchronous Operation

Related pages:

• Angular Tutorials

Angular SlicePipe

Syntax:
{{ value_expression | slice : start [ : end ] }}

– value: an Array or a String.
– start (number): the starting index of the returned subset ->

• if a positive integer -> return the item at start index and all items after in the list or string expression. In case start is greater than the size of the expression -> an empty list or string is returned
• if a negative integer -> return the item at start index from the end and all items after in the list or string expression. In case start is greater than the size of the expression -> an empty list or string is returned

– end (number): the ending index of the returned subset ->

• omitted -> all items until the end will be returned
• if positive -> all items before end index will be returned
• if negative -> all items before end index from the end will be returned

Practice

SlicePipe with Array and String Example

We create a slice-pipe component as below:
– slice-pipe.component.ts ->

import { Component, OnInit } from '@angular/core';

@Component({
  selector: 'app-slice-pipe',
  templateUrl: './slice-pipe.component.html'
})
export class SlicePipeComponent {
  array: string[] = ['one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight'];
  str: string = 'qwertyuopasdfghjkl';
}

– slice-pipe.component.html ->

<h3>SlicePipe Array</h3>
<ul>
    <li *ngFor="let i of array | slice:2:5">{{i}}</li>
</ul>
<h3>SlicePipe String</h3>
String's value: <strong>{{str}}</strong>
<p>slice [0:6]: '{{str | slice:0:6}}'</p>
<p>slice [6:1]: '{{str | slice:6:1}}' (start > end)</p>
<p>slice [-1]: '{{str | slice:-1}}'</p>
<p>slice [-5]: '{{str | slice:-5}}'</p> 
<p>slice [-5:-2]: '{{str | slice:-5:-2}}'</p>
<p>slice [-50]: '{{str | slice:-50}}' (-start < -string.length)</p>
<p>slice [50]: '{{str | slice:50}}' (start > string.length)</p>

Result

SourceCode

– Project structure ->

– SourceCode ->

AngularSlicePipe

Last updated on April 24, 2021.