3rd lesson Go control, loop, select, jump statement

This is a creation in Article, where the information may have evolved or changed.

 PackageMainImport("FMT")funcMain () {/* Go retains pointers, but unlike other programming languages, pointer operations and the "-to" operator are not supported in go, but are directly "." Selector to manipulate the pointer target object's member operator "&" to take the variable address, using "*" to indirectly access the target object by pointer to the default nil instead of NULL * /A: =1    varP *int= &a FMT. Println (*P)//Output 1    //Hands    /* + + and--is used as a statement instead of an expression expression can be placed on the = right so now a++ can only be used as a separate line */a--FMT. Println (*P)//Output 0    if1<2{//Zoda brackets must be placed on the IF same line}a usage of//if    ifA: =1; A >1{//initialization statement; Conditional Statement}Another use of//if, note that the scope of a is only in the IF statement block    //And overwrite a above, when the if executes, a becomes an external statement of a    /* Loop statement for-go only for one loop statement keyword, but supports three forms of initial-initialization and stepping expressions can be multiple values-The conditional statement is re-examined each time, so it is not recommended in the conditional language Use a function in a sentence, try to calculate the condition in advance and replace it with a variable or constant-the opening brace must be in the same line as the conditional statement */Fmt. Println ("-----") AA: =1     for{aa++ifAA >3{ Break} FMT. PRINTLN (AA)} FMT. Println ("Over")//First formFmt. Println ("-----") forAA <=3{aa++ FMT. PRINTLN (AA)}//Second formFmt. Println ("-----") forI: =0; I <3; i++ {fmt. Println ("The Third Kind")    }//Third form (step expression)    / * SELECT statement Switch-you can use any type or expression as a conditional statement-no write break required-if you want to continue with the next case, you need to use the Fllthrough statement-support An initialization expression (which can be in parallel) with a semicolon-left brace must be on the same line as the conditional statement * /Fmt. Println ("-----") B: =1    SwitchD = Case0: FMT. Println ("A=0") Case1: FMT. Println ("A=1")default: FMT. Println ("None")} FMT. Println ("-----")SwitchBB: =1; {//The scope of this BB is also within the code block     CaseBB >=0: FMT. Println ("Bb>=0") CaseBB >=1: FMT. Println ("Bb>=1")default: FMT. Println ("None")} FMT. Println ("-----")/ * Jump statement goto,break,continue-Three syntax can be used with the label-the label name is case-sensitive, if you create a label without using a compile error-break and continue mate tag can be The bounce-goto for multi-layer loops is the adjustment execution position, which is not the same as the result of the other 2 statement mates */LABEL1: for{ forI: =0; I <Ten; i++ {ifi >3{ BreakLABEL1}}} fmt. Println ("Jump out of the loop!")//Using the break LABEL1 will jump out of the same level of rotation as the LABEL1, noting that the same level of loops as LABEL1    //Obviously if you use Goto, you will adjust the execution position, infinite loop down    //If you use continue, you will also jump out of the LABEL1 level loop, where there is an infinite loop, which must be adjusted as follows:LABEL2: forI: =0; I <Ten; i++ { for{ContinueLABEL2 FMT. Println (i)//This clause will never be executed}} FMT. Println ("Jump out of the loop!")//If you change contain to Goto, the result will be an infinite loop! }

Operation Result:
1
0
—–
2
3
Over
—–
—–
Third Kind
Third Kind
Third Kind
—–
A=1
—–
Bb>=0
—–
Jump out of the loop!
Jump out of the loop!