Console.assert 断言

接受2个参数

第一个参数转换为boolean值为true，什么也不做

第一个参数转换为boolean值为false，assert打印第二个参数的返回值（基本为字符串）

    console.assert(true,"assert true");
    console.assert(1,"assert 1");
    console.assert("ss","assert string");
    console.assert([],"assert empty array");
    console.assert({},"assert empty object");
    console.assert(false,"assert false"); //Assertion failed: assert false
    console.assert(0,"assert 0");//Assertion failed: assert 0
    console.assert(null,"assert null");//Assertion failed: assert null
    console.assert(undefined,"assert undefined");//Assertion failed: assert undefined
    console.assert(undefined,alert(1));// Assertion failed: undefined