下列JavaScript语句中能正确执行的是___________ 。
A: document.printf("Welcome to You!");
B: var x=5;if (x) {alert("Hello World! ");}
C: var z,if;
D: {var x=4,y=9;alert("Hello World! ");
A: document.printf("Welcome to You!");
B: var x=5;if (x) {alert("Hello World! ");}
C: var z,if;
D: {var x=4,y=9;alert("Hello World! ");
B
举一反三
- 下列JavaScript语句中能正确执行的是( )。 A: x=10,document.write(x+y); B: var sum=x+y; C: var x=1;if (x==1) {alert("Hello World! ");} D: var x=1;if (x==1) then {alert("Hello World! " );}
- 下面代码的运行结果是( )。var str= "hello world" ;var str1=str.toUpperCase();var str2=str.toLowerCase() ;alert (str1) ;alert (str2) ; A: "HELLO WORLD","HELLO WORLD" B: "HELLO WORLD","hello world" C: "hello worl","HELLO WORLD" D: "hello world","hello world"
- 程序段如下:var x = new Boolean(false);if (x) { alert('hi');}var y = Boolean(0);if (y) { alert('hello');}最后的显示结果是( ) A: hi B: hi hello C: hello D: 不显示
- 下列变量命名错误的是( )。 A: var _hello; B: var $hello; C: var $x_$y; D: var %x;
- 在JavaScript基本语法中,下列写法正确的是( ) A: window.alert("Hello World!"); B: window.alert(Hello World!); C: alert("Hello World!"); D: alert(Hello World!);
内容
- 0
以下代码段执行后的输出结果为( ) var x =-3; var y =-10; alert(y%x);
- 1
11字符串测试1:下列字符串定义正确的是: A: String str="Hello World!"; B: Str str="Hello World!"; C: var str="Hello World!"; D: var str='Hello World!';
- 2
var x=3;var y=2;var z=(x+2)/y;alert(z);输出结果为( ) A: 2 B: 2.5 C: 32/2 D: 16
- 3
下列程序的运行结果是( )。var arr1=[1,2,3,4,5,6];var arr2=["hello","world"];var arr=arr1.concat(arr2);document.write(arr1); A: "hello","world" B: 1,2,3,4,5,6 C: 1,2,3,4,5,6,"hello","world" D: "hello","world",1,2,3,4,5,6
- 4
下列JavaScript语句可以正确执行的是______。 A: var x = 10; x = "222"; B: var x = "222"; x = 10; C: var x = "222"; x = parseInt(x); D: var x = NaN; x = parseInt(x);