The if-clause in JavaScript
The if-clause is equivalent to the Decision element that we used in the last chapter. It checks whether a condition has been met.
The JavaScript code for an if statement isn't that difficult. It is made up of a condition and the if-clause itself. The form looks like this:
|
Statement |
Example |
|---|---|
if (condition) {
code block
} else if (condition) {
code block
} else {
code block
} | if (varString == "test") {
varResult=true;
} else {
varResult=false;
} |
In the preceding example, the varString string is tested if it contains the word "test". If it does, the Boolean varResult is set to true. If it is not (the else part), it is set to false. The else if block can be added multiple times.
Conditions and operators
A condition is made up of a statement that is either true or false. This statement is built by using operators. The following are the operators that JavaScript knows:
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and |
or |
Not |
Equal |
Not equal |
Smaller |
Bigger |
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