All JavaScript Array Method here…
push(): adds one or more elements to the end of an array.
Example:
let fruits = ["apple", "banana"];
fruits.push("orange");
console.log(fruits); // ["apple", "banana", "orange"]
pop(): removes the last element from an array.
Example:
let fruits = ["apple", "banana", "orange"];
fruits.pop();
console.log(fruits); // ["apple", "banana"]
shift(): removes the first element from an array.
Example:
let fruits = ["apple", "banana", "orange"];
fruits.shift();
console.log(fruits); // ["banana", "orange"]
unshift(): adds one or more elements to the beginning of an array.
Example:
let fruits = ["banana", "orange"];
fruits.unshift("apple");
console.log(fruits); // ["apple", "banana", "orange"]
splice(): adds or removes elements from an array at a specified index.
Example:
let fruits = ["apple", "banana", "orange"];
fruits.splice(1, 1, "mango", "peach");
console.log(fruits); // ["apple", "mango", "peach", "orange"]
2. JavaScript String Methods:
indexOf(): returns the index of the first occurrence of a specified string in a string. Example:
let str = "Hello, world!";
console.log(str.indexOf("world")); // 7
slice(): extracts a section of a string and returns it as a new string. Example:
let str = "Hello, world!";
console.log(str.slice(0, 5)); // "Hello"
split(): splits a string into an array of substrings based on a specified separator. Example:
let str = "apple,banana,orange";
console.log(str.split(",")); // ["apple", "banana", "orange"]
replace(): replaces a specified value with another value in a string.
Example:
let str = "Hello, world!";
console.log(str.replace("world", "John")); // "Hello, John!"
3. JavaScript Math Methods:
ceil(): rounds a number up to the nearest integer. Example:
console.log(Math.ceil(4.2)); // 5
floor(): rounds a number down to the nearest integer. Example:
console.log(Math.floor(4.8)); // 4
- round(): rounds a number to the nearest integer. Example:
console.log(Math.round(4.5)); // 5
random(): returns a random number between 0 and 1. Example:
console.log(Math.random()); // 0.123456789 (random number)
functions in JavaScript
- Math functions:
- Math.abs(): returns the absolute value of a number. Example:
console.log(Math.abs(-5)); // 5
- Math.max(): returns the maximum value of a list of numbers. Example:
console.log(Math.max(1, 2, 3)); // 3
- Math.min(): returns the minimum value of a list of numbers. Example:
console.log(Math.min(1, 2, 3)); // 1
- Math.sqrt(): returns the square root of a number. Example:
console.log(Math.sqrt(16)); // 4
- String functions:
- String.fromCharCode(): returns a string created by using the specified sequence of Unicode values. Example:
console.log(String.fromCharCode(65, 66, 67)); // "ABC"
- String.indexOf(): returns the index of the first occurrence of a specified value in a string. Example:
let str = "Hello, world!";
console.log(str.indexOf("world")); // 7
- String.slice(): extracts a section of a string and returns it as a new string. Example:
let str = "Hello, world!";
console.log(str.slice(0, 5)); // "Hello"
- Array functions:
- Array.isArray(): returns true if an object is an array, and false if it is not. Example:
let arr = [1, 2, 3];
console.log(Array.isArray(arr)); // true
- Array.forEach(): executes a provided function once for each array element. Example:
let arr = [1, 2, 3];
arr.forEach(function(item) {
console.log(item);
}); // 1, 2, 3
- Array.map(): creates a new array by calling a provided function on each element in the array. Example:
let arr = [1, 2, 3];
let newArr = arr.map(function(item) {
return item * 2;
});
console.log(newArr); // [2, 4, 6]
- Array.reduce(): applies a function against an accumulator and each element in the array to reduce it to a single value. Example:
let arr = [1, 2, 3];
let sum = arr.reduce(function(accumulator, item) {
return accumulator + item;
});
console.log(sum); // 6
Nice Sharing JavaScript Notes
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