Trinocular operations: such as var a = 10;var b= 12;c = a>b? a:b; If you set up execute a otherwise execute bvar ishide = true; If you use the IF Judgment statement as follows if (ishide) {box.style.display = "block" ;} else {Box.style.display = "none";} Trinocular operation instead of Ifbox.style.display = Ishide? " Block ":" None "; judging the condition? Set up execution statement: Execution statement is not established. Conditions of return: establishment of the results of the implementation of the conditions are not valid: the results of the implementation of the simplified version of If judgment continue skip this cycle: Cannot write to the Trinocular operation column: for (var i=0;i<5;i++) {if (i==3) continue; Skip I= 3 This cycle does not carry out, others are still executed. }break: Terminates the entire loop; By default, only the next loop is terminated. If you want to terminate the other loops, you need to name the loop. Example: for (Var i=0;i<5;i++) {if (i==3) break; the entire loop is terminated when the loop executes to i=3. }name:for (Var i=0;i<5;i++) {for (Var j=0;j<5;j++) {Break name//Terminate two loops}} object storage data, is an attribute of the object that exists: the object is a complex type of data, We can store any type of data in the object The first: property operation 1 The one property operation is a set of dead values, and the variable cannot be used. Read Operation obj. property name write Operation obj. property name = attribute value; obj.key = val; key-value pair, such as var obj = {};obj.name = "Leo"; This notation is written for the first property names to be dead if you want to invoke the Obj.age = 40; Next Cons Ole.log (Obj.name);. Obj.gender = "female"; Console.log (OBJ.W);//Note that the first property operation is a value that is written dead, and you cannot use the variable OBJ.W to write the W property of obj. Second property operation the second property operation is to do, receive a string, the string can exist in the variable, can be directly written obj[variable call] read operation obj["property name]obj[" property name "]= attribute value; obj[" Key "= Val; note the second type Var obj = {};obj[' name '] = "Leo";obj[' age ' = 40;obj[' gender '] = "female"; obj[' width '] = "180px"; obj[' height '] = "180px"; obj[' children '] = ["Daming", "Xiaoming", "sanming "];var w =" width ";//Console.log (obj[w]);//The second property operation, accepts a string, the string can exist in the variable, can be directly written obj[variable call];alert (" name "in obj); Obj returns true with the Name property, otherwise false to determine if there is a property in the object that returns True or FalseFor (var s in obj) {All properties that find obj will turn into Arr's property name//the same over in method will change the loop variable s into obj to Console.log (S,obj[s]); The name of the property that should be. If you want to use only the second name. The type of S is a string. } S is the property name Obj[s] is the property value of the corresponding property name. for in can be used to loop objects and arrays cannot be used to loop a set of elements, for loops can only be used to loop arrays of array classes (a set of elements) that cannot be used to loop a set of objects. ## #while语句 # # #起始值while (judging condition) {EXECUTE statement; self-increment;} # #switch # #switch (to be judged) {case: the content of judgment;// After the condition is established, the execution statement executes all code in the case, and only the break will end the execution of the statement; If you do not meet the break, you will be executed with all the code. Break;default://Above all the judgments are not valid} example switch (a) {case 10://when a = = 10;console.logo (";;;") statement is added breakbreak;//when a==10 cases 15 ://When A==15;console.logo ("PPPPP") Break;default://Above all judgments are not established}
JS Switch to determine the trinocular operation while and property operation
