The if statement then checks for their equality and pops-up an alert box if the two variables are equal. The == comparison operator does the job of checking the two variables. The other Comparison operators are: != Not equal to < Less than > Greater than <= Less than or equal to >...
if (x >= 0) { // The if statement... return x; // executes this code if the comparison is true. } // This is the end of the if clause. else { // The optional else clause executes its code if return -x; // the comparison is false. } // Curly braces optional when 1 sta...
当JavaScript 中的变量被声明的时候,程序内部会给它一个初始值undefined。 当对一个值为undefined的变量进行运算操作的时候,算出来的结果将会是NaN,它的意思是 "Not a Number"。 当用一个值是undefined的变量来做字符串拼接操作的时候,它会转换成字符串(string)undefined。 null指代缺少(absence)值,undefined指代未...
delete y; // returns false (cannot delete if declared with var) delete Math.PI; // returns false (cannot delete predefined properties) delete myobj.h; // returns true (can delete user-defined properties) delete myobj; // returns true (can delete if declared implicitly) 9. 关系操作符 关...
Thisifstatement returnsfalse(as expected) because x is not equal to 10: letx =0; if(x ==10) Try it Yourself » Thisifstatement returnstrue(maybe not as expected), because 10 is true: letx =0; if(x =10) Try it Yourself » ...
// assigning a value to the variable `x`foo(x,y);// calling function `foo` with parameters `x` and `y`obj.bar(3);// calling method `bar` of object `obj`// A conditional statementif(x===0){// Is `x` equal to zero?x=123;}// Defining function `baz` with parameters `a`...
// A conditional statement if (x === 0) { // Is `x` equal to zero? x = 123; } // Defining function `baz` with parameters `a` and `b` function baz(a, b) { return a + b; } 注意等号的两种不同用法: 单个等号(=)用于将一个值赋给一个变量。
Problem statement: 问题陈述: Given an array which consists of0'sand1's, your task is to find the maximum lengths of the largest subarray with an equal number of0'sand1's. The test cases consist of array length and its elements. The first line of the input test cases is the array len...
JavaScript If Else statement The above code is OK if you only want to display something when the condition is true. But what if you want to display something when the condition is not true. For example, what if the variable myColor was equal to, say, Red? This is where an If Else ...
if the score variable is equal to 50. Otherwise, it displays You failed the examination.JavaScript if...else StatementIn computer programming, the if...else statement is a conditional statement that executes a block of code only when a specific condition is met. For example,Suppose...