Essential JavaScript

String Length

Strings are made of a sequence of characters. JavaScript allows us to count those characters.

Try running this code in the editor:

"my string".length

The result is 8. Each character, including the space, is counted.

length is a property that all strings have. Properties are values that belong to an object. We will work with objects and properties more later. For now, it is important to know that:

  • we use the dot operator (.) to access properties of an object
  • strings are objects
  • all strings have a length property that returns the number of characters in the string

Counting Escaped Characters

Try running this in the console:

"a \"healthy\" dessert".length

The result is 19. Both of the backslashes are ignored, as they escape the double quotation marks directly after them. The \" combo is treated as a single character.

Any escaped character will only be counted once, even though we have to type the backslash as an additional character.

In a Function

When we pass a string into a function as an argument, we access it by name of the argument. Run this function in the editor:

function countStringLength(theString) {
  return theString.length;
countStringLength("example text");

Learning Goals

Code Editor