What are parameters in java?

This article introduces what parameters are in Java, as well as the two types of parameters and the relationship between them. I hope it will be helpful to students learning Java development.

What are the parameters in java?

There are two types of parameters: one is called formal parameters, and the other is called actual parameters.

Formal parameters are separated by commas in parentheses after the method name, for example

public void coverAtoB(String str1, int i2) {
......
}

Of course, sometimes the method has no parameters

public void coverCtoD() {
......
}

str1 is a formal parameter of string type, and i2 is a formal parameter of integer type. If you want to use this method, you must When calling this method, pass it the actual values ​​of these two formal parameters (this is the actual parameter)

Example

coverAtoB("abc", 3);

(Related video tutorial sharing: java video Tutorial)

Formal parameters and actual parameters

1. Formal parameters: They are the parameters named when defining a function or procedure. In layman's terms, it is a mark.

2. Actual parameters: These are the parameters passed to the function or procedure when calling the function or procedure during execution. In layman's terms, it is the actual value.

3. A parameter is a variable variable that changes with different users.

For example, I learned the sin(x) function in middle school. The x here is the formal parameter. When you need to find the sine value of 1, you will use sin(1). The 1 here is It is the relationship between the actual parameters

The relationship between the formal parameters and the actual parameters: the two are combined when calling, usually the actual parameters will be The value is passed to the formal parameter. After the formal parameter is passed, the function process operation is performed, and then some values ​​may be returned to the caller through the parameter or function symbol.

The formal parameter is the parameter list when defining the function, which only defines the parameters. The structure of the table and the names used for reference have no specific content.

The actual parameter is the specific data passed by the calling function.

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