Fuels-ts

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String ​

In Sway, strings are statically-sized, which means you must define the size of the string beforehand. Statically-sized strings are represented using the str[x] syntax, where x indicates the string's size. This guide explains how to create and interact with statically-sized strings while using the SDK.

Creating Statically-Sized Strings ​

ts
// Sway str[2]
const stringSize2 = 'st';

// Sway str[8]
const stringSize8 = 'fuel-sdk';
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Interacting with Statically-Sized Strings in Contract Methods ​

When a contract method accepts and returns a str[8], the corresponding SDK wrapper method will also take and return a string of the same length. You can pass a string to the contract method like this:

ts
const { value } = await contract.functions.echo_str_8('fuel-sdk').simulate();

expect(value).toEqual('fuel-sdk');
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When working with statically-sized strings, ensure that the input and output strings have the correct length to avoid erroneous behavior.

If you pass a string that is either too long or too short for a contract method, the call will fail like this:

ts
const longString = 'fuel-sdk-WILL-THROW-ERROR';

await expect(async () => contract.functions.echo_str_8(longString).call()).rejects.toThrowError(
  'Value length mismatch during encode'
);

const shortString = 'THROWS';

await expect(async () =>
  contract.functions.echo_str_8(shortString).call()
).rejects.toThrowError('Value length mismatch during encode');
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