Web Notes
2016.08.20
Using Liquid in Jekyll - Live with Demos
Liquid is a simple template language that Jekyll uses to process pages for your site. With Liquid you can output complex contents without additional plugins.
Common built-in array methods in JavaScript
useful array methods
Note took from:
Freeman, Adam. Pro React 16. Berkeley, CA: Apress, 2019. https://doi.org/10.1007/978-1-4842-4451-7.
| Method | Description |
|---|---|
concat(otherArray) | This method returns a new array that concatenates the array on which it has been called with the array specified as the argument. Multiple arrays can be specified. |
join(separator) | This method joins all the elements in the array to form a string. The argument specifies the character used to delimit the items. |
pop() | This method removes and returns the last item in the array. |
shift() | This method removes and returns the first item in the array. |
push(item) | This method appends the specified item to the end of the array. |
unshift(item) | This method inserts a new item at the start of the array. |
reverse() | This method returns a new array that contains the items in reverse order. |
slice(start, end) | This method returns a section of the array. |
sort() | This method sorts the array. An optional comparison function can be used to perform custom comparisons. |
splice(index, count) | This method removes count items from the array, starting at the specified index. The removed items are returned as the result of the method. |
every(test) | This method calls the test function for each item in the array and returns true if the function returns true for all of the items and false otherwise. |
some(test) | This method returns true if calling the test function for each item in the array returns true at least once. |
filter(test) | This method returns a new array containing the items for which the test function returns true. |
find(test) | This method returns the first item in the array for which the test function returns true. |
findIndex(test) | This method returns the index of the first item in the array for which the test function returns true. |
forEach(callback) | This method invokes the callback function for each item in the array, as described in the previous section. |
includes(value) | This method returns true if the array contains the specified value. |
map(callback) | This method returns a new array containing the result of invoking the callback function for every item in the array. |
reduce(callback) | This method returns the accumulated value produced by invoking the callback function for every item in the array. |
Since many of the methods in the table return a new array, these methods can be chained together to process data. For example:
let products = [
{ name: "Hat", price: 24.5, stock: 10 },
{ name: "Kayak", price: 289.2, stock: 4 },
{ name: "Soccer Ball", price: 10.5, stock: 7 },
{ name: "Running Shoes", price: 233, stock: 0 }
]
let totalValue = products.filter(item => item.stock > 0)
.reduce((total, item) => total + item.stock * item.price , 0)
console.log(`Total value: $${totalValue.toFixed(2)}`);
Total value: $1475.30
THE END
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Frank Lin
Hey, there! This is Frank Lin (@flinhong), one of the 1.41 billion . This 'inDev. Journal' site holds the exploration of my quirky thoughts and random adventures through life. Hope you enjoy reading and perusing my posts.
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