# Quantifiers

Quantifiers indicate numbers of characters or expressions to match.

## Types

Note: In the following, item refers not only to singular characters, but also includes character classes and groups and backreferences.

## Examples

### Repeated pattern

In this example, we match one or more word characters with `\w+`, then one or more characters "a" with `a+`, and finally end at a word boundary with `\b`.

js
``````const wordEndingWithAs = /\w+a+\b/;
const delicateMessage = "This is Spartaaaaaaa";

console.table(delicateMessage.match(wordEndingWithAs)); // [ "Spartaaaaaaa" ]
``````

### Counting characters

In this example, we match words that have a single letter, words that have between 2 and 6 letters, and words that have 13 or more letters.

js
``````const singleLetterWord = /\b\w\b/g;
const notSoLongWord = /\b\w{2,6}\b/g;
const longWord = /\b\w{13,}\b/g;

const sentence = "Why do I have to learn multiplication table?";

console.table(sentence.match(singleLetterWord)); // ["I"]
console.table(sentence.match(notSoLongWord)); // [ "Why", "do", "have", "to", "learn", "table" ]
console.table(sentence.match(longWord)); // ["multiplication"]
``````

### Optional character

In this example, we match words that either end with "our" or "or".

js
``````const britishText = "He asked his neighbour a favour.";
const americanText = "He asked his neighbor a favor.";

const regexpEnding = /\w+ou?r/g;
// \w+ One or several letters
// o   followed by an "o",
// u?  optionally followed by a "u"
// r   followed by an "r"

console.table(britishText.match(regexpEnding));
// ["neighbour", "favour"]

console.table(americanText.match(regexpEnding));
// ["neighbor", "favor"]
``````

### Greedy versus non-greedy

In this example, we match one or more word characters or spaces with `[\w ]+` and `[\w ]+?`. The first one is greedy and the second one is non-greedy. Note how the second one stops as soon as it meets the minimal requirement.

js
``````const text = "I must be getting somewhere near the center of the earth.";
const greedyRegexp = /[\w ]+/;

console.log(text.match(greedyRegexp)[0]);
// "I must be getting somewhere near the center of the earth"
// almost all of the text matches (leaves out the dot character)

const nonGreedyRegexp = /[\w ]+?/; // Notice the question mark
console.log(text.match(nonGreedyRegexp));
// "I"
// The match is the smallest one possible
``````