is not a string javascript code example

Example 1: is string javascript

function isString(value) {
	return typeof value === 'string' || value instanceof String;
}

isString(''); // true
isString(1); // false
isString({}); // false
isString([]); // false
isString(new String('teste')) // true

Example 2: if string javascript

if (typeof myVar === 'string') { /* code */ };

Example 3: js check if variable is string

if (typeof myVar === 'integer'){
    //I am indeed an integer
}

if (typeof myVar === 'boolean'){
    //I am indeed a boolean
}