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How do I make the first letter of a string uppercase in JavaScript? Ask Question

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How do I make the first letter of a string uppercase in JavaScript? Ask Question

How do I make the first character of a string uppercase if it's a letter, but not change the case of any of the other letters?

For example:

  • "this is a test" → "This is a test"
  • "the Eiffel Tower" → "The Eiffel Tower"
  • "/index.html" → "/index.html"

ベストアンサー1

function capitalizeFirstLetter(string) {
    return string.charAt(0).toUpperCase() + string.slice(1);
}

Some other answers modify String.prototype (this answer used to as well), but I would advise against this now due to maintainability (hard to find out where the function is being added to the prototype and could cause conflicts if other code uses the same name/a browser adds a native function with that same name in future).

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