Test for array of string type in TypeScript
typescript
Solution
You cannot test for `string[]` in the general case but you can test for `Array` quite easily the same as in JavaScript https://stackoverflow.com/a/767492/390330 (I prefer `Array.isArray(value)`).
If you specifically want for `string` array you can do something like:
if (Array.isArray(value)) {
var somethingIsNotString = false;
value.forEach(function(item){
if(typeof item !== 'string'){
somethingIsNotString = true;
}
})
if(!somethingIsNotString && value.length > 0){
console.log('string[]!');
}
}
In case you need to check for an array of a class (not a basic type)
if(items && (items.length > 0) && (items[0] instanceof MyClassName))
If you are not sure that all items are same type
items.every(it => it instanceof MyClassName)
Problem
How can I test if a variable is an array of string in TypeScript? Something like this: ``` function f(): string { var a: string[] = ["A", "B", "C"]; if (typeof a === "string[]") { return "Yes" } else { // returns no as it's 'object' return "No" } }; ``` TypeScript.io here: http://typescript.io/k0ZiJzso0Qg/2 Edit: I've updated the text to ask for a test for string[]. This was only in the code example previously.