The in Operator
RUN
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> </head> <body> <h1>Học lập trình miễn phí tại freetuts.net</h1> <p id="result"></p> <button onclick="myFunction()">Run</button> <script> function myFunction() { var content; // Arrays var language = ["php", "js", "css", "html"]; content = content + 'Arrays :<br>' content = content + '0 in cars - ' + (2 in language) + '<br>'; content = content + '3 in cars - ' + (3 in language) + '<br>'; content = content + '0 in cars - ' + (4 in language) + '<br>'; content = content + 'php in cars - ' + ("php" in language) + '<br>'; content = content + 'css in cars - ' + ("css" in language) + '<br>'; content = content + 'lenght in cars - ' + ("lenght" in language) + '<br><br>'; // Objects var person = {firstName:"John", lastName:"Doe", age:50}; content = content + 'Objects :<br>' content = content + 'firstName in person - ' + ("firstName" in person) + '<br>'; content = content + 'lastName in person - ' + ("lastName" in person) + '<br>'; content = content + 'Doe in person - ' + ("Doe" in person) + '<br><br>'; // Predefined objects content = content + 'Predefined objects :<br>' content = content + 'PI in Math - ' + ("PI" in Math) + '<br>'; content = content + '3 in Number - ' + ("NaN" in Number) + '<br>'; content = content + '0 in String - ' + ("length" in String) + '<br>'; document.getElementById("result").innerHTML = content; }; </script> </body> </html>
PHÓNG TO