String Indexing and Length

The number of characters in a string, accessed as a property without parentheses.

Part of: JavaScript Coding without HTML and CSS — Module 29

Understanding String Indexing and Length in JavaScript

What it does: Since indexing starts at 0, index 1 is the second character. length is accessed directly as a property, not called as a method. Strings are indexed starting at 0, just like arrays. length counts every character in the string, including spaces. Square brackets [], not round brackets, access a character by index. JavaScript is case-sensitive, so it must be lowercase 'length'. Every [ used for indexing needs a matching ]. Index 0 always refers to the first character in a string.

Common mistakes: Use square brackets [], not round brackets, to access a character. Use square brackets [], not round brackets, to access a character.

Class: _____________________ · Name: _____________________ · Date: _________

Free printable worksheet with full answer key — or add this module to a class and your students practise it interactively.

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This module's key terms are also in a printable crossword (Modules 21–30) and word search (Modules 1–29) and word search (Modules 21–52).

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Each concept is reinforced from every angle — learned, then applied, then tested.

Learning

Duo

Does word[0] access the first character of a string?

YesNo

Matches

console.log(word(0));

↓

Wrong - use square brackets, not round brackets

Applying

Meanings

Term

length

Meaning

The number of characters in a string, accessed as a property without parentheses.

Practice

let word = "hello";

Testing

Gaps

console.log(word0]);

Check Answer

Spots

1console.log(word(0));

2let word = "cat";

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Quick Questions

1. Does word[0] access the first character of a string?

A. Yes ✓

B. No

Strings are indexed starting at 0, just like arrays.

2. Does .length give the number of characters in a string?

A. Yes ✓

B. No

length counts every character in the string, including spaces.

3. Is () used instead of [] to access a character?

A. Yes

B. No ✓

Square brackets [], not round brackets, access a character by index.

4. Does .length need parentheses after it, like .length()?

A. Yes

B. No ✓

length is a property, not a method, so no parentheses are needed.

5. Is 'Length' with a capital L valid JavaScript syntax?

A. No ✓

B. Yes

JavaScript is case-sensitive, so it must be lowercase 'length'.

Match the Pairs

word[0] → Accesses the first character of the word string

word.length → Gives the total number of characters in word

Accesses the second character of a string → name[1]

A property that never needs parentheses → length

console.log(word(0)); → Wrong - use square brackets, not round brackets

console.log(word.length()); → Wrong - length is a property, not a method

Key Term

length

The number of characters in a string, accessed as a property without parentheses.

Fill in the Blanks

1. console.log(word[0]);

Hint: Type the symbol that opens an index access.

2. console.log(word.length);

Hint: Type the property that gives a string's number of characters.

3. let ch = word[1];

Hint: Type the index of the second character.

4. let name = "Amy"; console.log(name.length);

Hint: Type the property that gives a string's number of characters.

5. let size = name.length;

Hint: Type the property that gives a string's number of characters.

Spot the Error

Question 1

A console.log(word(0));

B let word = "cat";

C console.log(word.length);

Line A — Use square brackets [], not round brackets, to access a character.

Question 2

A let text = "dog";

B console.log(text(1));

C console.log(text.length);

Line B — Use square brackets [], not round brackets, to access a character.

Question 3

A let text = "cat";

B console.log(text.length);

C console.log(text0]);

Line C — Missing the opening square bracket before the index.

Question 4

A let word = "sun";

B console.log(word[0]);

C console.log(word.length);

D console.log(word[1);

Line D — Missing the closing square bracket after the index.

Question 5

A let name = "Amy";

B console.log(name[0]);

C console.log(name[1]);

D console.log(name[2]);

E console.log(name.lenght);

Line E — 'length' is misspelled as 'lenght'.

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