The startsWith()
method of String
values determines whether this string begins with the characters of a specified string, returning true
or false
as appropriate.
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String.prototype.startsWith()
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Syntax
startsWith(searchString)
startsWith(searchString, position)
Parameters
-
searchString
-
The characters to be searched for at the start of this string. Cannot be a regex. All values that are not regexes are coerced to strings, so omitting it or passing
undefined
causesstartsWith()
to search for the string"undefined"
, which is rarely what you want. position
Optional-
The start position at which
searchString
is expected to be found (the index ofsearchString
's first character). Defaults to0
.
Return value
true
if the given characters are found at the beginning of the string, including when searchString
is an empty string; otherwise, false
.
Exceptions
-
TypeError
-
Thrown if
searchString
is a regex.
Description
This method lets you determine whether or not a string begins with another string. This method is case-sensitive.
Examples
Using startsWith()
const str = "To be, or not to be, that is the question.";
console.log(str.startsWith("To be")); // true
console.log(str.startsWith("not to be")); // false
console.log(str.startsWith("not to be", 10)); // true
Specifications
Browser compatibility
Desktop | Mobile | Server | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Opera | Safari | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | WebView Android | Deno | Node.js | ||
startsWith |
41 | 12 | 17 | 28 | 9 | 36 | 17 | 24 | 9 | 3.0 | 37 | 1.0 | 4.0.0 |
See also
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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/startsWith