应用函数javascript循环额外

我是Javascript的新手，创建了一个示例函数来测试Javascript的apply函数

我需要澄清一下这个代码

value-x将取第一个数组['val1'，'val2']，但只是想知道它是否替换为（这个，x）。。 2.我看到console.log中打印了3项，最后一项是-未定义，未定义，发生了什么

var dummyfunction1 = function(val1,val2){
    console.log(array1,array2);
};

[['val1','val2'],['val3','val4']].forEach(function(x){
    dummyfunction1.apply(this,x);
});

dummyfunction1()

---

这里有几个问题

dummyfunction1正在使用主体中未定义的变量。应该是这样的：

var dummyfunction1 = function(val1,val2){
    console.log(val1,val2);
};

var dummyfunction1 = function(val1,val2){
    console.log(val1,val2);
};

// this will automatically be run, no need to call dummyfunction1 on your own after this
[['val1','val2'],['val3','val4']].forEach(function(x){
    dummyfunction1.apply(this,x);
});

最后一行

dummyfunction1（）

正在对dummyfunction1进行无参数的附加调用。这是您看到的未定义的

完整代码如下所示：

var dummyfunction1 = function(val1,val2){
    console.log(val1,val2);
};

var dummyfunction1 = function(val1,val2){
    console.log(val1,val2);
};

// this will automatically be run, no need to call dummyfunction1 on your own after this
[['val1','val2'],['val3','val4']].forEach(function(x){
    dummyfunction1.apply(this,x);
});

---

这里有几个问题

dummyfunction1正在使用主体中未定义的变量。应该是这样的：

var dummyfunction1 = function(val1,val2){
    console.log(val1,val2);
};

var dummyfunction1 = function(val1,val2){
    console.log(val1,val2);
};

// this will automatically be run, no need to call dummyfunction1 on your own after this
[['val1','val2'],['val3','val4']].forEach(function(x){
    dummyfunction1.apply(this,x);
});

最后一行

dummyfunction1（）

正在对dummyfunction1进行无参数的附加调用。这是您看到的未定义的

完整代码如下所示：

var dummyfunction1 = function(val1,val2){
    console.log(val1,val2);
};

var dummyfunction1 = function(val1,val2){
    console.log(val1,val2);
};

// this will automatically be run, no need to call dummyfunction1 on your own after this
[['val1','val2'],['val3','val4']].forEach(function(x){
    dummyfunction1.apply(this,x);
});

---

这里有几个问题

dummyfunction1正在使用主体中未定义的变量。应该是这样的：

var dummyfunction1 = function(val1,val2){
    console.log(val1,val2);
};

var dummyfunction1 = function(val1,val2){
    console.log(val1,val2);
};

// this will automatically be run, no need to call dummyfunction1 on your own after this
[['val1','val2'],['val3','val4']].forEach(function(x){
    dummyfunction1.apply(this,x);
});

最后一行

dummyfunction1（）

正在对dummyfunction1进行无参数的附加调用。这是您看到的未定义的

完整代码如下所示：

var dummyfunction1 = function(val1,val2){
    console.log(val1,val2);
};

var dummyfunction1 = function(val1,val2){
    console.log(val1,val2);
};

// this will automatically be run, no need to call dummyfunction1 on your own after this
[['val1','val2'],['val3','val4']].forEach(function(x){
    dummyfunction1.apply(this,x);
});

---

这里有几个问题

dummyfunction1正在使用主体中未定义的变量。应该是这样的：

var dummyfunction1 = function(val1,val2){
    console.log(val1,val2);
};

var dummyfunction1 = function(val1,val2){
    console.log(val1,val2);
};

// this will automatically be run, no need to call dummyfunction1 on your own after this
[['val1','val2'],['val3','val4']].forEach(function(x){
    dummyfunction1.apply(this,x);
});

最后一行

dummyfunction1（）

正在对dummyfunction1进行无参数的附加调用。这是您看到的未定义的

完整代码如下所示：

var dummyfunction1 = function(val1,val2){
    console.log(val1,val2);
};

var dummyfunction1 = function(val1,val2){
    console.log(val1,val2);
};

// this will automatically be run, no need to call dummyfunction1 on your own after this
[['val1','val2'],['val3','val4']].forEach(function(x){
    dummyfunction1.apply(this,x);
});