How to Check If a String Is Empty in Go

In Go, check if a string is empty by comparing it directly to an empty string literal ("") using the equality operator. You can also check the length with len(s) == 0, but the direct comparison is generally preferred for readability.

Here are the two most common patterns:

package main

import "fmt"

func main() {
    s := ""

    // Method 1: Direct comparison (Recommended)
    if s == "" {
        fmt.Println("String is empty")
    }

    // Method 2: Length check
    if len(s) == 0 {
        fmt.Println("String length is zero")
    }
}

A common mistake is trying to use nil to check for an empty string. Unlike slices, maps, or pointers, strings are value types that cannot be nil. A string variable is always initialized to "" if not explicitly set, so s == nil will cause a compile-time error.

// This will fail to compile:
// if s == nil { ... } 

// Correct approach for optional strings (using pointers):
var ptr *string = nil
if ptr == nil || *ptr == "" {
    // Handle nil or empty
}

When dealing with whitespace-only strings (e.g., " "), the standard equality check returns false because the string contains characters. Use strings.TrimSpace() if you need to treat whitespace-only strings as empty:

import "strings"

s := "   "
if strings.TrimSpace(s) == "" {
    fmt.Println("String contains only whitespace")
}

For performance-critical loops where you are checking the same string repeatedly, the compiler optimizes s == "" and len(s) == 0 identically, so choose based on code clarity. The direct comparison s == "" is the idiomatic Go approach and is immediately understandable to any Go developer reading your code.

Checking if a string is empty in Go verifies if a text variable contains any characters. It counts the letters inside the string; if the count is zero, the string is empty. Think of it like checking if a box is empty by counting the items inside.