How to create an array of numbers in javascript
- Admin
- Nov 28, 2023
- Typescript Javascript
This tutorial covers multiple ways we can do to create an array with a sequence of numbers.
how to create an array of numbers for a given range in javascript?
Using for loop
with index assigned with initial number and increment by 1 until end of the number, and add an index to an array.
Here is an example to create an array of sequence numbers from 1 to 50.
var numbers = [];
for (var i = 1; i <= 50; i++) {
numbers.push(i);
}
console.log(numbers);
Output:
[
1, 2, 3, 4, 5,6, 7, 8, 9, 10
]
using the ES6 spread operator
es6 provides spread operatoruses to include an array of values of an array.
The generated sequence of numbers using the spread operator and keys method in es6
var array = [...Array(10).keys()];
console.log(array);
output:
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
Also, you can use Arrays.from() function in place of the spread operator
var array = Array.from(Array(10).keys());
console.log(array);
The above two examples generate numbers from zero.
if you want to generate from 1, Here is a code. It uses an arrow function with increment values by 1.
var array = Array.from(Array(10).keys(), (n) => n + 1);
console.log(array);
Output:
[
1, 2, 3, 4, 5,6, 7, 8, 9, 10
]
lodash range function
if the application uses the lodash library, It provides a range function that iterates with a range of min and max values. Syntax:
_.range([start], stop, [step]);
Here is an
start
: It is a starting number or initial number,
Stop
: is the maximum value that needs to increment too.
Step
: needs value which increments by how much value, Default is 1.
_.range(1, 10);
Output:
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
Underscore times function
times function uses to iterate the loop a given number of times and each iteration calls the callback function.
_.times(numberoftimes, callbackfunction);
number
: It iterates multiple times with the given call-back function.
callbackfunction
: This function called for each iteration
array = [];
_.times(5, function (i) {
array.push(i++);
});
Output:
[1, 2, 3, 4, 5]
Conclusion
Learn multiple ways to create an array of sequence numbers for a given min and max values in javascript.