Lesson Five Golang language variables

1 variables three kinds of declaration: ( the first kind of Var and type are redundant;

the second is the most concise, but the second can only be used in a function, not the declaration of a global variable.

The first type:

var v_name V_type ( note order = value

" FMT " Func Main () {    varint    123     Fmt. Println (vname1)    FMT. Println (vname2)    FMT. Println (Vname3)}

Second type: (initialization declaration)

If you are in the same code block, we cannot use the initialization declaration again for variables of the same name

var= value ( self-derived type )

" FMT " Func Main () {    var789    FMT. Println (v1)    FMT. Println (v2)    FMT. Println (v3)}

The third type:

: = Value (: = The variable on the left must be not declared )

2 value types and reference types

All basic types, such as int, float, bool, and string, are value types, using variables of these types to point directly to a value that exists in memory, and when an equal sign is used to = assign the value of a variable to another variable, such as: j = i , the value of I is actually copied in memory

&i to get the memory address of the variable I, for example: 0xf840000040 (each time the address may be different). The value of a variable of value type is stored in the stack.

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Lesson Five Golang language variables