Go Printing to Stdout and Stderr: Difference between revisions
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=Bootstrapping Functions= | =Bootstrapping Functions= | ||
Both <code>[[#print.28.29|print()]]</code> and <code>[[#println.28.29|println()]]</code> are [[Go_Language#Pre-Declared_Functions|pre-declared functions]], ready to use without any import. | Both <code>[[#print.28.29|print()]]</code> and <code>[[#println.28.29|println()]]</code> are [[Go_Language#Pre-Declared_Functions|pre-declared functions]], ready to use without any import. | ||
<font color=darkkhaki>TODO: https://golang.org/ref/spec#Bootstrapping</font> | |||
==<tt>print()</tt>== | ==<tt>print()</tt>== | ||
==<tt>println()</tt>== | ==<tt>println()</tt>== | ||
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} | } | ||
</syntaxhighlight> | </syntaxhighlight> | ||
=<tt>fmt</tt> Functions= | =<tt>fmt</tt> Functions= | ||
Revision as of 00:49, 6 September 2023
Internal
Bootstrapping Functions
Both print()
and println()
are pre-declared functions, ready to use without any import.
TODO: https://golang.org/ref/spec#Bootstrapping
print()
println()
func main() {
println("something")
}
fmt Functions
fmt.Printf()
import "fmt"
// ...
fmt.Printf("something %s", "blue")
Print()
expects a format specifier (or a format string) as the first argument, which contains conversion characters (ex. %s
):
Strings
color := "blue"
fmt.Printf("The color is %s\n", color)
Integers
size := 1
fmt.Printf("The size is %d\n", size)
Characters
c := 'x'
fmt.Printf("The character is %c\n", c)
Booleans
b := true
fmt.Printf("The boolean value is %t\n", b)
Floating Point Numbers
f := 1.0
fmt.Printf("The floating point value is %f\n", f)
Pointers
s := "something"
sPtr := &s
fmt.Printf("pointer value: %p\n", sPtr)
"%p"
prepend the "0x" prefix.
Pointers can be also represented using "%X"
(base 16, upper case characters).