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SyntaxError: missing name after . operator

Error type


What went wrong?

The dot operator (.) is used for property access. You will have to specify the name of the property that you want to access. For computed property access, you might need to change your property access from using a dot to using square brackets. These will allow you to compute an expression. Maybe you intended to do concatenation instead? A plus operator (+) is needed in that case. Please see the examples below.


Property access

Property accessors in JavaScript use either the dot (.) or square brackets ([]), but not both. Square brackets allow computed property access.

var obj = { foo: { bar: "baz", bar2: "baz2" } };
var i = 2;

// SyntaxError: missing name after . operator

// SyntaxError: missing name after . operator

To fix this code, you need to access the object like this:

obj.foo.bar; // "baz"
// or alternatively
obj["foo"]["bar"]; // "baz"

// computed properties require square brackets
obj.foo["bar" + i]; // "baz2"

Property access vs. concatenation

If you are coming from another programming language (like PHP), it is also easy to mix up the dot operator (.) and the concatenation operator (+).

console.log("Hello" . "world");

// SyntaxError: missing name after . operator

Instead you need to use a plus sign for concatenation:

console.log("Hello" + "World");

See also

Tag del documento e collaboratori

 Hanno collaborato alla realizzazione di questa pagina: fscholz
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