JavaScript foreach loop statement is an advanced version of for loop. Java array forEach method iterates over the array items, in ascending order, without mutating the array.
Syntax
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array.forEach(function(currentValue, index, array), thisValue) |
Parameter Values
Function is required to be run for each element in the array.
- currentValue:– The current element being processed in the array.
- index:- The array index of the current element. (Optional)
- array:- The array object the current element belongs to
thisArg:- Value to use as this when executing callback.
Example of JavaScript foreach loop
Let’s do example of sum of all the values in the array.
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<!DOCTYPE html> <html> <body> <script type="text/javascript"> var sum = 0; var numbers = [65, 44, 12, 4]; numbers.forEach(myFunction); function myFunction(item) { sum += item; } alert(sum) </script> </body> </html> |
Output:
How to Javascript foreach string in list(Array)
Example of print index and its value of JS array using foreach loop.
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<!DOCTYPE html> <html> <body> <p id="demo"></p> <script> var fruits = ["A", "B", "C"]; fruits.forEach(myFunction); function myFunction(item, index) { document.getElementById("demo").innerHTML += index + " : " + item + "<br>"; } </script> </body> </html> |
Output:
Q: How to forEach push to array JavaScript?
Answer: Let’s copy all the values from one array to another array using the Javascript foreach function and Javascript push() function.
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<!DOCTYPE html> <html> <body> <script> const elements = [11, 21, 46]; const copy = []; elements.forEach(function(element){ copy.push(element); }); console.log(copy); </script> </body> </html> |
Output: [11, 21, 46]
Do comment if you have any questions and suggestions on this tutorial.
Note: The All JS Examples codes are tested on the Safari browser (Version 12.0.2) and Chrome.
OS: macOS 10.14 Mojave
Code: HTML 5 Version
Degree in Computer Science and Engineer: App Developer and has multiple Programming languages experience. Enthusiasm for technology & like learning technical.