Tengo by Example: String Formatting

String Formatting

Wikipedia: printf format string
fmt.sprintf formats a string using Go-style verbs and returns it. fmt.printf writes the formatted output directly.

fmt := import("fmt")

%s formats a string, %d an integer, %f a float.

fmt.println(fmt.sprintf("Hello, %s!", "Tengo"))
fmt.println(fmt.sprintf("%d + %d = %d", 3, 4, 7))
fmt.println(fmt.sprintf("Pi ~ %.4f", 3.14159))

Width and alignment: use a number before the verb. Negative width left-aligns.

fmt.println(fmt.sprintf("|%10s|%-10s|", "right", "left"))

%v is the default representation, useful for any value.

fmt.println(fmt.sprintf("%v", [1, 2, 3]))
fmt.println(fmt.sprintf("%v", {a: 1}))

Integer bases: %b binary, %o octal, %x hex.

fmt.println(fmt.sprintf("%08b", 42))
fmt.println(fmt.sprintf("%x", 255))

fmt.printf writes directly to output.

fmt.printf("formatted: %d\n", 99)

try it

Hello, Tengo!
3 + 4 = 7
Pi ~ 3.1416
|     right|left      |
[1, 2, 3]
{a: 1}
00101010
ff
formatted: 99

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