What are the forms and usages of if statements in java

Form 1: if statement

The if statement means that if a certain condition is met, a certain process will be performed. For example, Xiao Ming’s mother said to Xiao Ming, “If you get 100 points in the exam, I will take you to the amusement park on Sunday.” This sentence can be described by the following pseudocode.

If Xiao Ming got 100 points in the exam
Mom took Xiao Ming to the amusement park on Sunday

In the above pseudocode, "if" is equivalent to the keyword if in Java, "Xiao Ming took the exam "Scored 100 points" is the judgment condition and needs to be enclosed in (). "Mom took Xiao Ming to the amusement park on Sunday" is the execution statement and needs to be placed in {}. The modified pseudocode is as follows:

if(小明考试得了100分){
              妈妈星期日带小明去游乐场
}

The above example describes the usage of the statement. In Java, the specific syntax format of the if statement is as follows:

if(条件语句){
       代码块
}

Above In the format, the judgment condition is a Boolean value. When the judgment condition is true, the execution statement in {} will be executed.

Form 2: if...else statement

The if...else statement means that if a certain condition is met, a certain process will be performed, otherwise another process will be performed. . For example, to determine the parity of a positive integer, if the number is divisible by 2, it is an even number, otherwise the number is an odd number. The specific syntax format of the if...else statement is as follows:

if(判断条件){
      执行语句1
}else{
     执行语句2
}

In the above format, the judgment condition is a Boolean value. When the judgment condition is true, the execution statement 1 below will be executed. When the judgment condition is false, execution statement 2 in {} after else will be executed.

Form 3: if…else if…else statement

if…else The if…else statement is used to judge multiple conditions and perform a variety of different processes. . For example, a student's test scores are graded. If the score is greater than 80 points, the grade is excellent. Otherwise, if the score is greater than 70 points, the grade is good. Otherwise, if the score is greater than 60 points, the grade is medium. Otherwise, the grade is poor. . if...else The specific syntax format of the if...else statement is as follows:

if(判断条件1){
        执行语句1
}
else if(判断条件2){
       执行语句2
}
…
else if(判断条件n){
       执行语句n
}else{
       执行语句n+1
}

In the above format, the judgment condition is a Boolean value. When the judgment condition 1 is true, the execution statement 1 in the following {} will be executed. When judgment condition 1 is false, judgment condition 2 will continue to be executed. If it is true, sentence 2 will be executed, and so on. If all judgment conditions are false, it means that all conditions are not satisfied. The { in else follows Execution statement n 1 will be executed.

Recommended tutorial: java introductory tutorial

The above is the detailed content of What are the forms and usages of if statements in java. For more information, please follow other related articles on the PHP Chinese website!