First words

A string has words. It contains a sentence, a paragraph. Words are separated with spaces. With a special func we can extract the first words in the sentence.

By counting spaces, we can estimate the number of words. This is not perfect. Extra logic to handle hyphens and punctuation might be needed.

Example func

The firstWords func receives to arguments: a string and a count. The count int is the number of words in our result.

package main

import "fmt"

func firstWords(value string, count int) string {
    // Loop over all indexes in the string.
    for i := range value {
        // If we encounter a space, reduce the count.
        if value[i] == ' ' {
            count -= 1
            // When no more words required, return a substring.
            if count == 0 {
                return value[0:i]
            }
        }
    }
    // Return the entire string.
    return value
}

func main() {
    value := "there are many reasons"

    // Test our first words method.
    result1 := firstWords(value, 2)
    fmt.Println("[" + result1 + "]")

    result2 := firstWords(value, 3)
    fmt.Println(result2)

    result3 := firstWords(value, 100)
    fmt.Println(result3)
}
[there are]
there are many
there are many reasons

Entire string, notes

If you pass a large value to firstWords, like 100, the entire string is returned. The argument 0 may need to be special-cased depending on your requirements.

Substrings are complex

Each language has special syntax for them. In Go we use a slice of a string. We can extract parts of strings, like the first several words, with this syntax.