How to Extract a Substring in JavaScript

substr, substring, slice, and more

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There are three methods for extracting part of a string in JavaScript, maybe too many. One would have been enough

substr

The substr(start, length) method extracts part of a string, beginning at the specified index and returning the specified number of characters.

const quote = "Winter is coming";
const part1 = quote.substr(0, 6);
//Winter
const part2 = quote.substr(10, 6);
//coming

Notice that the first character is at index 0.

The start index is required but the length is optional. If omitted it extracts the rest of the string.

const quote = "Winter is coming";
const part = quote.substr(6);
// is coming

substring

The substring(start, end) method returns the part of a string between the start and end indexes. It begins with the character at the start index and ends but does not include the character at the end index.

const quote = "We Stand Together";
const part = quote.substring(3, 8);
// Stand