TUTORIAL · STEP 3 OF 7

Strings and vectors

A std::string is a JavaScript string. A std::vector is a vector object, with two helpers that turn it into an array and back.

split returns a std::vector<std::string>, which arrives as a vector object: size() and get(i) read it, and Module.toArray(vector) copies it into an array.

total takes a std::vector<int>, so it needs a vector object too. Module.toVector('VectorInt', [1, 2, 3, 4]) builds one from an array; the first argument names the vector type.

In an app, initNative() runs the module in a Web Worker by default. Every call returns a promise there, and plain arrays are converted for you. The playground runs the module without a worker, so calls return their results directly and vectors take the helpers.

Try it

Add std::vector<int> range(int from, int to); and print Module.toArray(Module.range(1, 5)).

#pragma once
 
#include <string>
#include <vector>
 
// std::string crosses as a JavaScript string.
std::string shout(const std::string &text);
 
// A returned std::vector arrives as a vector object:
// size() and get(i) read it; Module.toArray makes an array.
std::vector<std::string> split(std::string text, char separator);
 
// A std::vector parameter takes a vector object;
// Module.toVector builds one from an array.
int total(const std::vector<int> &values);
 
 
#pragma once

#include <string>
#include <vector>

// std::string crosses as a JavaScript string.
std::string shout(const std::string &text);

// A returned std::vector arrives as a vector object:
// size() and get(i) read it; Module.toArray makes an array.
std::vector<std::string> split(std::string text, char separator);

// A std::vector parameter takes a vector object;
// Module.toVector builds one from an array.
int total(const std::vector<int> &values);

Runs without a compile until you edit the C++.

Console

Press Run, or Ctrl+Enter, to run main.js.