If-Else
The if construct allows executing code fragments, if a certain condition is true. The optional else part executes some other code, if the condition is false.
Syntax
if(expression) {
// code_if_true
} else {
// code_if_false
}
Parts
- expression is a condition.
Example
int a = 2;
int b = 5;
if(a > b) {
log.message("true\n");
} else {
log.message("false\n");
}
// output: false
You can use if and else separetely.
int a=2;
if(a == 2) log.message("a is equal to 2\n");
// the result is: a is equal to 2
Note that if you use a complex boolean expression as a condition, the expression will be evaluated from the left to the right (short-circuit evaluation):
int func(int a) {
return a;
}
// there will be only one (the first) call of func()
if(func(0) && func(1)) log.message("true\n");
// func() will be called twice
if(func(1) && func(1)) log.message("true\n");
// there will be only one (the first) call of func()
if(func(1) || func(1)) log.message("true\n");
// func() will be called twice
if(func(0) || func(1)) log.message("true\n");
Last update: 03.07.2017
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