go语言中Add是什么
时间: 2023-07-08 16:44:59 浏览: 60
在Go语言中,`Add`通常是指对整数类型的加法操作。例如,在使用sync/atomic包时,`Add`可以用于对一个整数类型进行原子性的加法操作。另外,在Go语言中的一些数据结构中,比如sync.Map和sync.Pool,也会使用到`Add`方法。在这些数据结构中,`Add`通常用于对某个计数器或者某个池的数量进行增加操作。
相关问题
go语言的函数的关键字是什么
### 回答1:
Go 语言的函数的关键字是 `func`。
例如:
```
func greet(name string) string {
return "Hello, " + name
}
```
在这个例子中,`func` 是用来声明一个函数的关键字。这个函数名为 `greet`,它接受一个字符串类型的参数 `name`,并返回一个字符串类型的值。
### 回答2:
Go语言的函数的关键字是"func"。在Go语言中,函数定义要使用关键字"func",后面紧跟着函数名和参数列表。函数的主体由花括号括起来,放在函数定义的下一行。通常情况下,函数名以小写字母开头表示其为私有函数,只能在所属的包内调用;若以大写字母开头,则表示该函数是公有函数,可在其他包中调用。例如,下面是一个简单的函数定义示例:
```go
func add(a, b int) int {
return a + b
}
```
这个函数名叫做"add",它接受两个参数a和b,两个参数的类型都是整数int,函数的返回值类型也是整数int。函数主体中只有一句代码,即返回a+b的结果。
通过关键字"func",我们可以定义各种不同功能的函数。函数是Go语言中重要的编程构建块,可以用于实现代码的封装、复用和模块化。
### 回答3:
Go语言的函数的关键字是"func"。在Go语言中,使用"func"关键字来定义和声明函数。函数是程序中完成特定任务的独立单元,它可以接受输入参数并可以返回一个或多个结果。函数的一般结构是:
```go
func 函数名(参数列表) (返回值列表) {
// 函数体
}
```
其中,函数名是标识函数的唯一名称,参数列表是函数输入的参数,可以为空或包含多个参数,返回值列表是函数输出的结果,可以为空或包含多个返回值。函数体是函数具体执行的代码块。
例如,下面是一个简单的Go函数的例子,用于计算两个整数的和并返回结果:
```go
func add(x int, y int) int {
return x + y
}
```
需要注意的是,Go语言的函数支持多返回值,可以在返回值列表中指定多个返回值。同时,Go语言还支持匿名函数和闭包的特性,使得函数应用更加灵活和强大。
go语言的爱心代码是什么
```
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<style>
* {
padding: 0;
margin: 0;
}
html,
body {
height: 100%;
padding: 0;
margin: 0;
background: #000;
}
canvas {
position: absolute;
width: 100%;
height: 100%;
}
.aa {
position: fixed;
left: 50%;
bottom: 10px;
color: #ccc;
}
</style>
<body>
<canvas id="pinkboard"></canvas>
<script>
/*
* Settings
*/
var settings = {
particles: {
length: 500, // maximum amount of particles
duration: 2, // particle duration in sec
velocity: 100, // particle velocity in pixels/sec
effect: -0.75, // play with this for a nice effect
size: 30 // particle size in pixels
}
};
/*
* RequestAnimationFrame polyfill by Erik M?ller
*/
(function () {
var b = 0;
var c = ["ms", "moz", "webkit", "o"];
for (var a = 0; a < c.length && !window.requestAnimationFrame; ++a) {
window.requestAnimationFrame = window[c[a] + "RequestAnimationFrame"];
window.cancelAnimationFrame =
window[c[a] + "CancelAnimationFrame"] ||
window[c[a] + "CancelRequestAnimationFrame"];
}
if (!window.requestAnimationFrame) {
window.requestAnimationFrame = function (h, e) {
var d = new Date().getTime();
var f = Math.max(0, 16 - (d - b));
var g = window.setTimeout(function () {
h(d + f);
}, f);
b = d + f;
return g;
};
}
if (!window.cancelAnimationFrame) {
window.cancelAnimationFrame = function (d) {
clearTimeout(d);
};
}
})();
/*
* Point class
*/
var Point = (function () {
function Point(x, y) {
this.x = typeof x !== "undefined" ? x : 0;
this.y = typeof y !== "undefined" ? y : 0;
}
Point.prototype.clone = function () {
return new Point(this.x, this.y);
};
Point.prototype.length = function (length) {
if (typeof length == "undefined")
return Math.sqrt(this.x * this.x + this.y * this.y);
this.normalize();
this.x *= length;
this.y *= length;
return this;
};
Point.prototype.normalize = function () {
var length = this.length();
this.x /= length;
this.y /= length;
return this;
};
return Point;
})();
/*
* Particle class
*/
var Particle = (function () {
function Particle() {
this.position = new Point();
this.velocity = new Point();
this.acceleration = new Point();
this.age = 0;
}
Particle.prototype.initialize = function (x, y, dx, dy) {
this.position.x = x;
this.position.y = y;
this.velocity.x = dx;
this.velocity.y = dy;
this.acceleration.x = dx * settings.particles.effect;
this.acceleration.y = dy * settings.particles.effect;
this.age = 0;
};
Particle.prototype.update = function (deltaTime) {
this.position.x += this.velocity.x * deltaTime;
this.position.y += this.velocity.y * deltaTime;
this.velocity.x += this.acceleration.x * deltaTime;
this.velocity.y += this.acceleration.y * deltaTime;
this.age += deltaTime;
};
Particle.prototype.draw = function (context, image) {
function ease(t) {
return --t * t * t + 1;
}
var size = image.width * ease(this.age / settings.particles.duration);
context.globalAlpha = 1 - this.age / settings.particles.duration;
context.drawImage(
image,
this.position.x - size / 2,
this.position.y - size / 2,
size,
size
);
};
return Particle;
})();
/*
* ParticlePool class
*/
var ParticlePool = (function () {
var particles,
firstActive = 0,
firstFree = 0,
duration = settings.particles.duration;
function ParticlePool(length) {
// create and populate particle pool
particles = new Array(length);
for (var i = 0; i < particles.length; i++)
particles[i] = new Particle();
}
ParticlePool.prototype.add = function (x, y, dx, dy) {
particles[firstFree].initialize(x, y, dx, dy);
// handle circular queue
firstFree++;
if (firstFree == particles.length) firstFree = 0;
if (firstActive == firstFree) firstActive++;
if (firstActive == particles.length) firstActive = 0;
};
ParticlePool.prototype.update = function (deltaTime) {
var i;
// update active particles
if (firstActive < firstFree) {
for (i = firstActive; i < firstFree; i++)
particles[i].update(deltaTime);
}
if (firstFree < firstActive) {
for (i = firstActive; i < particles.length; i++)
particles[i].update(deltaTime);
for (i = 0; i < firstFree; i++) particles[i].update(deltaTime);
}
// remove inactive particles
while (
particles[firstActive].age >= duration &&
firstActive != firstFree
) {
firstActive++;
if (firstActive == particles.length) firstActive = 0;
}
};
ParticlePool.prototype.draw = function (context, image) {
// draw active particles
if (firstActive < firstFree) {
for (i = firstActive; i < firstFree; i++)
particles[i].draw(context, image);
}
if (firstFree < firstActive) {
for (i = firstActive; i < particles.length; i++)
particles[i].draw(context, image);
for (i = 0; i < firstFree; i++) particles[i].draw(context, image);
}
};
return ParticlePool;
})();
/*
* Putting it all together
*/
(function (canvas) {
var context = canvas.getContext("2d"),
particles = new ParticlePool(settings.particles.length),
particleRate =
settings.particles.length / settings.particles.duration, // particles/sec
time;
// get point on heart with -PI <= t <= PI
function pointOnHeart(t) {
return new Point(
160 * Math.pow(Math.sin(t), 3),
130 * Math.cos(t) -
50 * Math.cos(2 * t) -
20 * Math.cos(3 * t) -
10 * Math.cos(4 * t) +
25
);
}
// creating the particle image using a dummy canvas
var image = (function () {
var canvas = document.createElement("canvas"),
context = canvas.getContext("2d");
canvas.width = settings.particles.size;
canvas.height = settings.particles.size;
// helper function to create the path
function to(t) {
var point = pointOnHeart(t);
point.x =
settings.particles.size / 2 +
(point.x * settings.particles.size) / 350;
point.y =
settings.particles.size / 2 -
(point.y * settings.particles.size) / 350;
return point;
}
// create the path
context.beginPath();
var t = -Math.PI;
var point = to(t);
context.moveTo(point.x, point.y);
while (t < Math.PI) {
t += 0.01; // baby steps!
point = to(t);
context.lineTo(point.x, point.y);
}
context.closePath();
// create the fill
context.fillStyle = "#ea80b0";
context.fill();
// create the image
var image = new Image();
image.src = canvas.toDataURL();
return image;
})();
// render that thing!
function render() {
// next animation frame
requestAnimationFrame(render);
// update time
var newTime = new Date().getTime() / 1000,
deltaTime = newTime - (time || newTime);
time = newTime;
// clear canvas
context.clearRect(0, 0, canvas.width, canvas.height);
// create new particles
var amount = particleRate * deltaTime;
for (var i = 0; i < amount; i++) {
var pos = pointOnHeart(Math.PI - 2 * Math.PI * Math.random());
var dir = pos.clone().length(settings.particles.velocity);
particles.add(
canvas.width / 2 + pos.x,
canvas.height / 2 - pos.y,
dir.x,
-dir.y
);
}
// update and draw particles
particles.update(deltaTime);
particles.draw(context, image);
}
// handle (re-)sizing of the canvas
function onResize() {
canvas.width = canvas.clientWidth;
canvas.height = canvas.clientHeight;
}
window.onresize = onResize;
// delay rendering bootstrap
setTimeout(function () {
onResize();
render();
}, 10);
})(document.getElementById("pinkboard"));
</script>
</body>
</html>
```
![示例图片](https://devbit-static.oss-cn-beijing.aliyuncs.com/devbit-static/img/heart.png)